I think a lot of people buy too much into the PIS that is associated with Hulk. First of all, he shouldn't be able to even garner any sort of win against characters like SS, Superman & Gladiator. The only way to even have such fights is to downgrade those characters and make them slow enough to hit. In their prime, Hulk should never be able to touch them & they should speed blitz him so hard he doesn't even have the time to know what's going on, not to talk of getting angry.
Another thing is the 'limitless strength' thing that i'll address in 2 ways. First of all, limitless strength is practically useless since his invulnerability doesn't grow with it & his powers don't multiply. Take the ground from under his feet & he's rendered useless. Use a constant supply of energy capable of tearing through his flesh & he's vaporized in minutes if not seconds (As seen when Gladiator used HV against him, but was stupid enough to stand in one spot while Hulk was moving towards him).
Also, there is an obvious limit to his strength because there is an obvious limit to anger. You can only get so angry & your body can only produce so many anger-inducing chemicals. Having your entire family killed seems to pretty much top it. You can't say that someone stepping on your toes or even punching you in the face after your family has just been killed would make you angrier than that. Hence his reaching his limit while fighting the Sentry.