Ok, I'll give you my list anyway
:
1) One-above-all (he's usually only mentiond and serves as "God" in the Marvel Universe)
2) Thanos in "Marvel Universe: The End" (he absorbs the Heart of Infinite and becomes so strong he annihilates even the Living Tribunal)
3) Living Tribunal (guardian of the
multiverse---> that is, not only of Earth-616; near-omnipotent)
4) possessor of the Infinity Gauntlet (like Thanos, again
---> shown to be less powerful than the Living Tribunal)
5) Death, Infinity, Eternity and possibly some other abstract entities
6) Galactus and possibly some other abstract entities
7) Celestials (but I'm just guessing... they could be as powerful as Galactus or even more... what do you think??)
8) Beyonder and Molecule Man (but WHAT are they?? Are they two parts of a Cosmic Cube? Is the Beyonder only a mutant inhuman? I don't know, but in Secret Wars he was shown able to easily defeat Galactus! And that would place him number 5 or even 4 in this list... what do you think??)
9) some GREAT god-like characters like Odin, Zeus, the Watchers, Stranger... of course i also count their immense power, and not only their (still great) physical strength
10) Hulk (I would have put him behind the present-day Thor -with the Odin power- but recent comics show Hulk as the strongest "human-or-so" Marvel character... moreover, we have to admit that there are no upper limits to the strength level he can reach, so he is -at least potentially- number one among all Earth -or Earth-like- beings..)
11) Thor (he has the Odin power, so I put him before Silver Surfer...)
12) Sentry (but maybe he is as powerful as Thor), Rulk (I think...)
13) Silver Surfer, Thanos
14) Juggernaut, Hercules
15) Abomination, Absorbing Man (potentially), Magneto (because of his magnetic powers), Gladiator (Kallark), Iron Man (not always, but the most powerful of his armors can be class 100...)
16) Thing, She-Hulk
17) Wonder Man
18) Black Bolt (WHY do they insist in putting him among the three or four most powerful characters in the Marvel Universe?? He is not!)
Well, what do you think?
And where would you place Mephisto??