On one hand, he likes a lot of hyper-educational shows for the nerdy set -- just about anything on the History channel that features someone with an English accent talking in a very serious monotone, for instance. But on the other hand, I think he also likes anything really cheesy and exploitative. He liked Jerry Springer, back when it was popular, and I know he likes COPS. In that vein, he likes various reality shows, if only for the trainwreck factor.
He watches the news, of course, and he likes The Daily Show and The Colbert Report. He also likes cartoons for adults -- South Park, Futrama, The Simpsons, etc. -- and anime.