Gregory House. He's a Vicodin addict, a lunatic, an ass to his co-workers and patients. Yet, I can't get enough of him.
If I had my way, when the series ended it would end with Cuddy and House getting married, Cameron coming back from wherever she is and remarrying Chase, and everyone would have a bunch of kids. I would make a terrible screenwriter.
House. I'm starting to see a pattern in the tv shows I like ... They all have a slightly autistic just-too-smart-to-be lead man (well except Merlin but he's got magic he doesn't need the autism lol)