Just about anything, so long as it's good. Good doesn't necessarily mean popular, and popular doesn't necessarily mean good. I think my #1 opinion here is that mine is the only one that matters to me. Too often music gets dismissed as crap just because it's on the radio. Too often good music onthe radio gets dismissed as crap because it's over played.
(For the record, I usually lean towards pop-rock or not so twangy country)