I was looking back and I saw the argument about Thor holding back against the Hulk. I think I can not only prove that wrong but that Hulk holds back when fighting most of the time.
He belives he has shown his superiority to Thor, so he stops fighting while Thor admits he was lost in the battle thanks to his Ego: http://img78.imageshack.us/img78/2883/thormt385q1wi.jpg
Another time Hulk smashes Thor into a hole in the ground, and then walks away. He has to know that Thor isn't dead: http://img159.exs.cx/img159/4041/thorih2001b5ku.jpg
Hulk vs. Norvell. Hulk stops multiple swings from Norvell's hammer. (Norvell and his hammer are equal in power to Thor and Mjolnir.) IH #422 (D: I'm not sure about the claim to them being equal, but it looks close. And this is a Hulk holding back too. Unfortunately I don't have access to my comics to verify the end of this fight)
http://img255.imageshack.us/img255/133/norvell1a7rc.jpg
http://img146.imageshack.us/img146/1539/norvell1b4hz.jpg
http://img113.echo.cx/img113/3614/norvell1c7fj.jpg
http://img146.echo.cx/img146/8590/norvell1d3zv.jpg
http://img383.imageshack.us/img383/5085/norvell1e1sc.jpg
http://img383.imageshack.us/img383/7289/norvell1f4jl.jpg
Hulk vs. Thor IH #440 - (D: Cut to when Thor stops 'Holding back' and after)
http://img128.imageshack.us/img128/9763/thorih440g0ok.jpg
http://img189.echo.cx/img189/5756/thorih440h7zp.jpg
http://img189.echo.cx/img189/9498/thorih440i1tq.jpg
http://img128.imageshack.us/img128/606/thorih440j4ux.jpg
http://img128.imageshack.us/img128/4999/thorih440k5wp.jpg
http://img128.imageshack.us/img128/746/thorih440l5ho.jpg
http://img84.exs.cx/img84/3118/nuke54wz.jpg
Grey Hulk vs. "Pineapple" Thing, round two. Thing, having just beaten Doom's robot Hulk, is confronted by the real deal once more. IH #350. (D: Again, cut to the Holding Back part, even Fixit wants to prov he's better without Killing his 'rivals'😉
http://img85.imageshack.us/img85/3016/thingih350i3mq.jpg
http://img85.imageshack.us/img85/4446/thingih350j6vl.jpg
http://img85.imageshack.us/img85/7374/thingih350k7de.jpg
And while I do not have access to my comics right now, RIGHT AFTER finding out that the Abomination was the one to kill Betty in a government lab, Hulk still holds back and doesn't kill the soldiers around him despite them spraying him with bullets and a flamethrower to the face.
And the fact that he hasn't killed hundreds of thousands of soldiers at this point also speaks for his holding back. A Bloodlusted Hulk won't be doing that.
OT: Thor comments on how limitless Hulk's strength seems 😄 http://img78.echo.cx/img78/5857/thormt385n4pr.jpg
Another scene of Hulk saying how much angrier he's gotten supporting Unlimited Rage: http://img145.exs.cx/img145/4783/genis5qn.jpg Remember, with Gamma mutants, it's all about Self Image.