What should I put on a mix cd for a 17 year old boy?

A guy friend of mine turns 17 on thursday. I want to make him a mix cd but im not really sure what to put on it. He doesn't really have one favorite "type" of music so it's kinda hard. I know he likes Dave Mathews, John Mayer, and Kanye. Does anyone have any ideas of songs I can put on the cd?