Hopefully Usher. He's a legend and everyone loves him. He has more than enough hits for at 12-minute show, and his career could use a little boost at the moment (no shade).
I'd also like Rihanna, Gaga and Britney to do it. I'm also here for a Latin-themed halftime show with Shakira, J. Lo, Ricky Martin, Romeo Santos and Prince Royce. That would be cool.