Well today my friends I will give you my own assessment on who I think are the top ten most powerful heroes.
About the list:
-Does not included celestial/cosmic powers such as the Jean Grey in her Phoniex form.
-Super hero vs Super hero battles will be taken into account.
-Will included heroes from Marvel, D.C., and Image Comics.
Well lets get started!
# 10 The Green Lantern
D.C. Hero

The Green Lantern is part of a small coalition of universal cops composed of many different races. These specially chosen individuals are given rings of power to uphold justice and maintain universal stability. Each Green Lantern is assigned a sector in the universe to patrol.
All of the Green Lantern's abilities stem from the power of his or her ring. The ring itself is powered by the users willpower and it is a very versatile weapon. The Green Lantern can use his ring to summon a shield, make a giant weapon, or even use it as a tractor beam. Really there is very little he Green Lantern cannot do with the ring, which makes him a strong choice for the #10 spot on the list.
#9 The Hulk
Marvel Hero

One day Dr. Robert Bruce Banner was experimenting with gamma rays. Accidentally, Dr. Bruce Banner blasted himself with these rays transforming him into the Hulk, a giant green behemoth with unsurpassed physical power.
The Hulk boast a variety of powers. The most obvious one is super strength, but the Hulk also has phenomenal regeneration abilities and is nearly indestructible. On top of all these powers the Hulk also becomes more powerful as he fights, meaning in a long fight the Hulk has the potential to be the strongest Super Hero.
Quick note: I see a lot of comments pertaining to how the Hulk is the strongest hero ever and that Superman nor Sentry compare to him. This is false, both Superman and Sentry have a much higher base strength than the Hulk and it would take the Hulk a long time to reach their level, much less surpass it.
The Hulk vs The Green Lantern: The Green Lantern is tough and his ring may last on a almost never ending supply of willpower, but the Hulk would be the victor in the end. The Hulks sheer power and brute force would quickly overpower the Green Lantern.
#8 Spawn
Image Comics Hero

Spawn was once a man who worked for the CIA. However Spawn's boss had him killed for knowing a bit too much. Upon his death Spawn was sent to hell. In the fiery dimension full of brimstone, Spawn made a deal with devil that allowed him to go back to Earth as part demon. Spawn accepted the offer and now seeks revenge on those who betrayed him.
To start off, Spawn is extremely fast, strong, and durable. He can only be killed by being decapitated by a heavenly weapon and controls an array of magical powers. However his magical powers are finite so he cannot use them too often.
Spawn vs The Green Lantern: The Green Lantern is powerful, but Spawn is fast, clever, and strong with a host of magical powers. Spawn could overpower the Green Lantern easily.
Spawn vs The Hulk: It would be a long difficult battle. Both combatants have super strength and regeneration, although the Hulk has faster regeneration and is stronger. However Spawn still holds an advantage here being more tactical and clever than the Hulk.
#7 Thor
Marvel Hero

Thor is the son of Odin who is basically a god and king of all the other gods in Asgard. That already should be enough of a reason of why he is so powerful.
Thor wields a mighty battle hammer called Mjnor into battle. This magical hammer is the source of Thor's power and enables him to control some aspects of the weather and fly. Thor also posses super strength comparable to Superman.
Thor vs The Green Lantern: Thor would easily beat the Green Lantern. I can't really think of anything the Green Lantern could do that could actually cause any serious damage to Thor.
Thor vs The Hulk: The Hulk is not nearly as strong as Thor when he starts out, nor is he has fast. Thor has the advantage here in both strength and speed.
Thor vs Spawn: Thor has some experience in fighting demons which already puts him at an advantage. Thor is not only stronger than Spawn, but his magical powers are infinite while Spawns are finite and any magic used against Thor would be absorbed by his hammer.
#6 Black Bolt
Marvel Hero

Black Bolt was an inhuman part of a genetics experiment. At birth, his parents soon discovered he had strong manipulation of energy which was especially potent through the use of his voice. Sometime later in his life Black Bolt shot down an enemy ship through use of his powers. However, the ship it ended up crashing into his parents ship and killing them instantly. Ever since then Black Bolt has been extremely careful when he uses his voice, in fact he never talks unless in combat, since even a small whisper from him can level an entire city. Recently Black Bolt has helped The Avengers and the Fantastic Four in various missions, even though during their first encounter Black Bolt completely destroyed the Fantastic Four.
Black Bolt's powers include energy manipulation, most notably through his super sonic scream. Through energy manipulation he also has super strength, speed, and durability. It is said his Super Sonic scream at full power could make a planet explode.
Black Bolt vs The Green Lantern: There really isn't much competition here. Black Bolt would win easily, all he would have to do is scream and break down any of the green Lantern's shields.There's really nothing GL can do to stop Black Bolts attacks, nor is there much the GL can do either to really hurt Black Bolt.
Black Bolt vs the Hulk: The only time The Hulk was ever a threat to Black Bolt was during the World War Hulk series. Normal enraged Hulk stands no chance against Black Bolt.
Black Bolt vs Spawn: Black Bolt would quickly over power Spawn. Spawn has very few abilities to resist Black Bolts powers. He might get a few hits in, but would ultimately lose.
Black Bolt vs Thor: Thor is incredibly strong and fast, but Black Bolt is no pushover either. With a voice that can make an entire planet explode. Thor doesn't really stand a chance.
#5 Superman
D.C. Hero

Superman was born on a planet known as Krypton. He is the sole survivor of his home world and draws his immense strength and powers from the yellow sun. Superman has a crippling weakness to kryptonite which has been exploited many times against him.
Superman has a large arsenal of powers. Out of every single comic book hero that was ever created, Superman is undoubtedly the strongest. No one truly knows just how powerful he can become since he seems to hold back most of the time. The man of steel is also the third fastest superhero right behind Flash and the Silver Surfer. Superman posses the abilities to freeze foes with his breath or melt them with heat vision. He is invulnerable to most types of attacks, which makes him one of the most resilient hero ever created as well.
Superman vs The Green Lantern: Superman is way to fast for the green Lantern. Also like Thor and The Hulk, if Superman gets trapped by the rings power he can easily break it's hold. The ring can create extremely large powerful weapons, but Superman is extremely resilient and wouldn't take much damage from the rings power anyway.
Superman vs The Hulk: Superman has already beaten the Hulk, twice. While The Hulk has the potential to become stronger than Superman,Superman's starting base power is much higher than the Hulks. He is also faster and and versatile which gives him an edge against the green behemoth.
Superman vs Spawn: Spawn is powerful, and he does have magic which is one of Superman's weaknesses. The problem with Spawn is however his magic is limited, and Spawns usual weapons won't work on Superman too effectively.
Superman vs Thor: This is an epic battle I would love to see happen. Thor has a magical hammer that is effective against Superman, but in the end Superman is simply too strong and too fast for Thor to keep up with.
Superman vs Black Bolt: While Black Bolt at full power may be able to destroy an entire planet, Superman has survived the core of a Star exploding. It's safe to say that Black Bolt will give Superman a good fight, but in the end Superman would prevail.
#4 Dr. Strange
Marvel Hero

Dr. Strange became the apprentice of a powerful entity known as the ancient one after suffering an accident that effectively ended his medical career. After many years of training, the Ancient One asked Dr. Strange to take his place, thus handing the title of Sorcerer Supreme to Dr. Strange.
Dr. Strange is The Supreme Sorcerer of the Universe, and his power pretty much limitless. He can create bolts of magic so powerful they can level a city, or restrain heroes like the Hulk with magic bonds. Dr. Strange can also use magic to make himself much more resilient than the average human, and is by no means frail.
Dr. Strange vs The Green Lantern: Dr. Strange's magic is much more powerful than the Green Lanterns ring. The Green Lantern would be overpowered within a few minutes.
Dr. Strange vs The Hulk: Dr. Strange has defeated the Hulk several times. His magic is simply to powerful for the Hulk to overcome, not to mention that he is a much smarter fighter than the Hulk.
Dr. Strange vs Spawn: Most of the enemies Dr. Strange fights are demons. Dr. Strange would have no trouble quickly dispatching Spawn.
Dr. Strange vs. Thor: Thor is highly magic resistant. This would be a tough fight for Strange but he could still pull it off.
Dr. Strange vs Black Bolt: Dr. Strange is willing to go farther than Black Bolt to win a fight. While Black Bolt may hold back on using his full power Strange certainly won't.
Dr. Strange vs Superman: Superman has three weakness: Kryptonite, Red Sun radiation, and Magic. You could make the argument that Superman is vastly faster and stronger than Strange, but Strange is Sorcerer Supreme, and Superman has never done well against magical foes.
#3 Sentry
Marvel Hero

Robert Reynolds was a high school student who happened to drink the secret formula of one of his Professors. After defeating the school bully with his newly acquired powers, Robert Reynolds decided from there on he would become a Superhero. He renamed himself Sentry.
The Sentry's powers are similar to Superman's: invulnerability, flight, super strength. Sentry nearly equals Superman in all these areas except Strength, and on top of that Sentry has physic abilities that even rival that of Professor X and Phoenix. Many speculate he has more powers that are not known yet.
Sentry vs Green Lantern: Like Superman, Sentry is to fast and powerful for the Green Lantern even to touch.
Sentry vs The Hulk: The Sentry absolutely destroys the Hulk. The Hulk can't beat Superman, and he sure as hell can't beat Sentry.
Sentry vs Spawn: The Sentry is extremely resistant to any of Spawns attacks, including his limited magic.
Sentry vs Thor: Thor is fast and strong, but Sentry is faster and stronger. Thor's magical Hammer won't help him out much here either, since Sentry is extremely resilient towards it.
Sentry vs Black Bolt: Black Bolt really can't match Sentry in terms of speed and strength.
Sentry vs Superman: While Superman has physical advantages over Sentry, Sentry also has physic abilities. With these abilities Sentry could subdue Superman into defeat.
Sentry vs Dr. Strange: As i stated before, Sentry is very resistant to most attacks including magic. Dr. Strange is pure magic, he won't be able to harm Sentry that much, on the other hand however Sentry will be able to do a lot of damage to Dr. Strange.
#2 The Silver Surfer
Marvel Hero

Not much is known about the Silver Surfer. We know his name is Norrin Radd, and out of desperation to save his planet, he begged Galactacus to make him his herald in order to save his planet. Glactacus accepted the proposal and gave Norrin Radd a portion of his cosmic powers to be his herald.
Instead of asking the question what can the Silver Surfer do, it's better to ask what can this mother fucker do? To start off he can travel at speeds faster than light it self, making him the fastest hero to ever have been created. He is nearly indestructible, can phase through matter, fire particle beams, has super strength, can create illusions, expand his size, is resistant to any type of extreme temperatures or poison, can heal wounds (although he cannot raise the dead), and create life.
The Silver Surfer vs The Green Lantern: The Silver Surfer can fly circles around the Green Lantern and manipulate the ring to not work for him.
Silver Surfer vs The Hulk: Another easy match for the Surfer. He can fly around the Hulk all day and simply keep blasting him until the giant green behemoth collapses from exhaustion.
Silver Surfer vs Spawn: Spawn really can't do anything against invulnerable foes like the Surfer. Even magic doesn't phase him!
Silver Surfer vs Thor: Thor really doesn't stand a chance. The surfer is fast and stronger than Thor and can easily defeat the Asgardian God. Not to mention the Surfer can destroy Thor's hammer.
Silver Surfer vs Black Bolt: Black Bolt is potent at manipulating energy, but so is the Surfer. It would be an interesting fight to see, but in the end the Silver Surfer would probably win because of his sheer speed and strength.
Silver Surfer vs Superman: Superman is stronger and more resilient than the Surfer, but not nearly as fast. The Silver Surfer would probably be able to blast Superman with kryptonite or red sun radiation weakening the man of steel.
Silver Surfer vs Dr. Strange: Magic doesn't work well against the Surfer. Dr. Strange is pure magic and would lose quickly.
Silver Surfer vs Sentry: Sentry's only advantage is that he is stronger than the surfer. Physic attacks don't work well against the Surfer and Norrin Radd would probably blast Sentry into defeat.
Now are you ready for the number one hero, the most powerful of all heroes in comic book history?
Drum roll please!
#1 MOST POWERFUL HERO IN COMIC BOOK HISTORY
Frank Richards
Marvel Hero

Lol. I know he doesn't look like much but let me explain. Frank Richards got his incredible psionic powers from the cosmic rays his mother was exposed to, the same one that changed the fantastic four and gave them their powers. Richards had to place mind blocks on himself to restrain his power. Many people theorize that the blocks have faded over time making him even more powerful. At one point Richard lost his powers. The moment he gained them back however it actually temporarily disrupted the time space continuum. Now thats power.
*A NOTE FROM N-MAN* psionic: adj- pertaining to the telepathic, psychic, or paranormal (for those who were confused)
Frank Richard has incredible psionic abilities. His abilities are so powerful he can actually create pocket universes and rearrange matter on a cosmic level. When at full power, Frank Richards can fire enormous energy blast enough to destroy planets and has incredible telekinetic powers. He also has the ability to see into the future, although he cannot control this aspect of his power himself.
Richards is almost to powerful to be on the list, yet he just makes it. Even with the partial mind block, Richards is still powerful enough to defeat the other heroes on this list.
Frank Richards vs The Green Lantern: Frank Richard would blast the Green Lantern into non existence, and there is nothing the Green Lantern can do to stop him.
Frank Richards vs the Hulk: Frank Richards can easily destroy the Hulk with a few psionic blast. And if worse comes to worst Richards just send the Hulk into a pocket universe he creates.
Frank Richards vs Spawn: Spawn can't even touch Richards. He won't get then feet with in the Psionic titan without being incinerated to thrown hundreds of miles away by telekinesis.
Frank Richards vs Thor: Thor might be a God, but Richards can stop Thor right in his tracks and possibly destroy his hammer (yes Thor's hammer has been destroyed before, but it's not an easy task.)
Frank Richards vs Black Bolt: Richards has even stronger manipulation of energy than Black Bolt does. He could probably use Black Bolts attacks against him.
Frank Richards vs Superman: Frank Richards psionic ability would be powerful enough to even restrain Superman, one of the strongest heroes ever created. Richards would have no problems defeating Superman at all.
Frank Richards vs Dr. Strange: Richards can easily shield himself from Dr. Strange's attacks and then blast Strange into defeat with energy attacks
Frank Richards vs Sentry: This might be tough for Richards, however in the end Sentry would probably be defeated from exhaustion. He is nearly invulnerable, but blasts strong enough to destroy planets would even fatigue this powerful titan.
Frank Richards vs The Silver Surfer: This would be an interesting fight. The Silver Surfer is fast and strong, not to mention he can control energy and matter as well as Richards. Richards can't even throw The Silver Surfer into anther dimension since the Surfer has the ability to cross into other dimensions. In the end Richards would most like win, however it would not be an easy battle.