Probably Doom.
I'm still basking in the glory of early Thor/Hulk fights right now, when they usually ended in a stalemate rather than Hulk completely dominating Thor because Hulk got more popular over the years while Thor got less popular. Hell, Thor didn't even use his hammer in Journey into Mystery #112 and he stalemated the Hulk.
That was a long, long, long time ago, dude.
Hell, if I wanted to do that, I could go back to the mere early 1990's when Colossus actually used to have "magic resistance" against some black magic, such as during INFERNO. I bet not even one editor recalls that now.
Nowadays it seems every tanker has to seem "vulnerable for drama" except the Hulk, and somehow it's not supposed to make Hulk boring.
..for the record, Thor came back and WOMPED Rulk. And Thor is usually trying to control the fights with Hulk so that nobody (including either one of them) gets hurt....most of the time.
Apparently no one remembers that.
Audiences don't care about damage to a scene in a mega-fight anymore. If Superman punched Imperiax through 25 buildings and flattened Metropolis into a smoldering crater, no one in the audience would go, "Oh god, Superman killed thousands of people". They'd go, "Holy ****, Superman is THE MAN, this is my favorite comic moment EVAR!" and Wizard would write 50 articles about it. I mean, the series finale of JLU essentially did that (Superman punches Darkseid through about 5 buildings, smashes him into the ground, there were civilians in the background and the audience only cares HOW AWESOME IT IS). It's about damn time Thor laid the smack down on Hulk now and then. Or on anyone for that matter; JMS has gotten me used to Thor having focus in maybe 1 out of 3 of his
own issues.
Speaking of overpowered characters, now that Thor is back and badder than ever and we have this big event centered around him...do we really need Sentry around? I mean...what's he been doing?
I think the Sentry has worked better in Dark Reign than anywhere else. He doesn't work as a straight up hero, as he's a walking pile of faults and psychosis. He doesn't work as a replacement to Thor, and he's still built on retcons and lies in general. But as the Heel Bodyguard to a Heel Villain/Boss, he's very effective.
That said, I did like his little meeting with Moon Knight in VENGEANCE OF THE MOON KNIGHT #2.
(Speaking of which, was VENGEANCE OF THE MOON KNIGHT solicited in Jan. 2010? If not, then damn, debut orders must've been low!)