Two things:
1. Def Jam: Fight for NY was AMAZING. I don't even love rap. Didn't matter. That game was so much fun and so well designed.
2. A WCW Revenge or WWF No Mercy remake, or just something made with the No Mercy engine, with polished graphics/sound, would blow my mind. I could play that for another 15 years or whatever until they made another. So much fun.
Oh, and here's an extra third thing: I have Fire Pro Returns. It's cool. Getting hundreds of amazing CAWs is fun. But it just doesn't have the pick-up-and-play playability that the AKI games had and so it falls short for me.