Bring back Grey Hulk/Joe Fixit. I'll be the first to admit, I don't like the new direction Marvel Now is going with him. How he was done in The Avengers was perfect, but I can see how some people want a smarter Hulk that can contribute without losing the original idea of losing control. For me, the aspect of losing control and letting out anger has always been apart of Hulk and Banner's dynamic. With Fixit you still have that kind of set up along with a Hulk that's really smart enough to follow orders(Mostly).
Okay this is mainly me wanting Joe Fixit back because he really is my favorite version of Hulk.