But, since the Hulk isn't even the same size and scale as a Human being (even the biggest guy you could find wouldn't match up) the stand in would have to be animatronic. Both recent movies gave us an awesome looking Hulk, I just want more physical interaction between the actors and the Hulk.
There are plenty of ways to manage that on film. Put the actor on a box or the other actors in a hole. LOTR being a fine example of how you can work with scale seamlessly. Nomal Human : Hulk = Hobbit : Normal Human.
But, it doesn't really matter. At some point, they need to worry more about the Hulk's "performance" and character than about the special effects. I don't believe they've managed that more than spottily in either movie. You make the character compelling enough and the audience will make the leap in suspension of disbelief more willingly.