Monster Hunter!!!!!!!!!!!
Seriously, I think that taking console games and putting them on the Vita will move consoles, particularly GTA, CoD, FF, MGS etc. I know they have superior console versions, but my PS3 does not fit in my pocket
I think the other thing that might help will be if they actually sort out PS Suite, and so get Android games onto the Vita so that people get the best of both worlds (and I can play Max Payne 1 on my Vita)