I think She-Hulk is probably the way to go, and a nice flick on the nose for whoever it was who made the sexist comments about her a few weeks back. Say she's got sick and needs a blood transfusion but because whatever she has is so far progressed it needs to be some form of super-blood (it never made sense to me why they'd just use the blood of the Hulk in the comics, sounds like a really bad idea). Military uses the opportunity to nab Banner while the transfusion has him weakened, cue She-Hulk to go break him out. Maybe banner would need to teach her his methods of control, which would also act as an explanation to why he had Hulk-on-tap in Avengers
