Here's what happens...
1. Presence and TOAA are God, both would stalemate each other and utterly destroy everything in DBZU...
2. Superman beats Gladiator
3. Supes would beat Sentry(someone wants to say more powerful versions of Sentry like void or DS takes Superman, well Superman at his best would stomp Sentry be it SA version, CA, Prime 1 million, AS whatever....)
4. Superboy and Hyperion are more even but this depends on the version of Superboy, I mean talking Pre 52 Superboy? Or New 52 Superboy? Or Superboy Prime? lol
5. Anti-Monitor destroys Galactus, not even close. AM is a muliversal buster. Galactus is barely a galaxy buster and needs heralds to scout planets for him to feed...
6. While this is even in some ways I believe Darkseid has the edge here, I know people say "Thanos with IG, HOTU blah, blah" but that's the thing Thano's best feats are with those power gimmicks, that being said DS should have Anti Life Equation or Darkness Saga versions which can match those versions of Thanos, however take all power gimmicks from both and Darkseid smacks Thanos via Omega Sanction(which is powered by the source which is more powerful than anything Thanos has. Darkseid even impressed Galactus when they did their crossover and made Galactus leave Apokolips when Galactus was in DCU...
7. Captain Marvel from DCU should win here, he's taken on Superman for a while as well as Black Adam not exactly two easy foes to take on.
8. Wonder Woman stomps, she's also gone toe to toe with the rest of the JL, Superman, Darkseid, Doomsday for quite a while New 52 she's the Goddess of War and has taken on or beaten GL, Superman, Darkseid, Doomsday, Ares, Black Adam, Mongul, Faora and Zod....
9. MMH mindrapes Piccollo, game over. Even if this fails he has other options.
10. While Hulk is relentless and strong, he lost to Superman who got killed by Doomsday and gives him trouble most of the time. Doomsday adapts and never really dies, plus becomes stronger in mid battle. Doomsday will turn Hulk into green putty at the end of the day. If you use H/P I feel bad for Hulk, New 52 DD even if Hulk tears him apart as Superman did DD's toxic spores will kill him and do him in given his lack of control over rage more times than not. And unlike Clark, Hulk wouldn't survive a blackhole and back. Either way, Doomsday>>>>>>>>Hulk.
11. Green Lantern should win here, however I'd also say this depends on which GL. If it's Hal, Kyle they will own Nova. If it's Simon Baz or just a regular GL Nova MAY have a chance.
12. Dr. Fate will wins here if you use Pre 52 or most at their best, if you use current versions Dr. Strange will most likely win...however if you use both at their best classic Fate would win. While classic strange is powerful, Dr. Fate helmet of Nabu has stalemated and taken on The Spectre for a longass time before eventually losing. Spectre is the vengence of God/Presence and essentially apart of him so yeah...
13. Flash stomps Quicksilver, no contest....Flash can go as fast as QS and THEN some. He's faster than Superman and faster than anyone really. The Speed Force allows the user to go as fast as they need to be, they have gone and surpassed lightspeed, can speed steal other users among other ridiculous things.
14. Human Torch is cool and all but lacks the same abilities that Firestorm has at the end of the day, Firestorm can do everything Human Torch can do but HT can't do everything FS can do...so giving the win to Firestorm.
15. Stalemate, this battle is pointless as neither can really do anything to harm the other. Clayface and Sandman may as well be the same thing just made from different material lol.
16. Red Tornado is powerful, but I think Vision will win in the end. Has more tools to work with than RT does, Vision is more or less in a lot of ways Marvel's MMH mixed with Cyborg.
17. Hawkman for the win, better armor, weapons and fighting skills. Not to mention magical weapons and the ability to heal, regen Katar gives him the win over Archangel, any version....Hawkman survived getting his arm ripped off, explosions in space and left for dead in the New 52. He will win.
18. Brainiac beats Apocalpse bad, while Apocalypse is a powerful mutant. Brainiac has proven to be a universal threat and soon he'll be a multiversal threat in DC's upcoming convergence so with that power amp ensures Brainiac stomps the mutant.
19. Batman, I know IM has the armored suit but considering Batman's ridiculous feats, better prep skills and tends to get into people's heads which Bruce would use against Tony here he'd figure out a way to exploit Tony's weaknesses and counter Tony's suits with suits of his own...besides, Batman has taken down the JL with prep, outsmarted them among many others and even held his own or outsmarted Darkseid. Tony won't be a problem considering who Batman tangos with. I'm sure tech wise, Iron Man is smarter than Bruce but detective wise, general prep wise and skill wise Batman is smarter.
20. Stalemate, however from a smart perspective one can argue Reed has the edge but I believe Plastic Man and Reed would be at it a while lol while taking out the others. Also no elongated man?
21. Will go with Steve here, Captain America he has better feats, the shield and overall taken down or competed with stronger foes than Guardian has.
22. Regardless of Logan's healing, Lobo will kill him...he has many ways to do such be it pure strength, overpowering Wolverine, or simply throwing him into space...Lobo is simply too much for Wolverine. He has given Superman trouble at times and other JL's who would one shot Wolverine. Lobo wins here.
23. Aquaman should win here in the end, I know both are virtually even but giving the edge to Aquaman due to better abilities and strength. He's taken on WW, Superman among others like Darkseid.
24. Going with Atom, pretty much what Antman can do Atom can do better. I also believe he's smarter overall than Hank is.
25. Would say this is very, very even actually though probably lean Lizard in the end here due to being smarter.
26. Green Arrow wins here, he's simply better then the other two with the bow and has shown better and more impressive feats from taking on better, stronger goes to literally shooting a bow in a gun barrel from ridiculous distances...
27. This match has tons of debate, honestly depends on the rules here...if we're talking longevity, Deadpool will win due to his regen abilities eventually. If we're talking skills, deathblows or battle to immobilize the other. Going Deathstroke all day here. The guy has given the JL whole problems, Batman and is arguably the best assassin in comics or one of the best at least. DP relies on his regen abilities and purposely jobbers cause he can afford to. I'm not counting his non canon 4th wall killing everyone in marvel crap, that's just for shits and giggles like the dumb shit squirrel girl does. So ultimately this match can go either way depending on the rules set, that being said regardless of who wins DS is smarter and more skilled while DP is just as agile and more durable. Though, if we use New 52 DS with all his ridiculous armor I'd probably go him more times than not.
28. Going Deadshot here, Bullseye's good..Deadshots better.
29. Grodd has Beast no problem, physically he can match him. While Beast may be scientifically smarter than Grodd, Grodd's no dummy and has strong Telepathy which Beast has no answer for. Grodd wins.
30. Catwoman, more agiles, smarter and has given the Bat trouble here and there. She can handle Black Cat.
31. Personally think Bucky vs. Jason Todd would be more interesting, though that match I'd lean Jason personally but against Dick...I think it depends. If Dick has prep he can win, but random encounter or generally speaking he'd probably have trouble with Bucky. Dick is more agile, skilled in H2H than Bucky but Bucky has the metal arm and deadlier weapons which give him an edge. Unless Dick gets in close and has a lot of toys he'll probably lose here.
32. Black Widow dies the second Black Canary screams, H2H Canary can easily match Widow if not beat her. That combined with her powers gives BC the win.
33. This match up is interesting considering Cyborg has crazy tech and can hack just about anything he can get into, however Cable's telepathy could prove an issue however I don't know or can't recall if Cyborg is vulnerable to TP. His mind is a computer more or less, while MMH can get in his mind(Cable's TP isn't remotely close to J'onn's tp) but could play tricks on him. Cyborg has boom tube tech which could prove a serious problem for Cable. This is a tough one, think it can go either way depending on who exploits who's weaknesses first.
34. Going Orion, Starlord at the end of the day just can't match him. Plus Orion has beaten Darkseid, taken on Superman and has better feats overall. Orion takes it.
35. There is no "Spider-Man" in DCU, but assuming you mean Black Spider? Spider-Man stomps Black Spider easily.
As far as who is the most powerful being ever? Pretty much whichever character is God in every universe.
DC=Presence/God
Marvel=TOAA
MKU=Elder Gods
Star Trek=The Q
Lord of the Rings=Eru
etc, etc
All of these are The God's of their respected universe, all are omnipotent and can do anything but also why they hardly directly get involved because they're the creator of their own universes. As far as omnipotent deities are concerned.