Basically any sitcom - especially those that feature the lazy, clueless comedian Dad.
Desperate Housewives, Lost, Grey's Anatomy, American Idol, Survivor to name a few. I can respect that my friends and co-workers like these shows, but when I say that I don't watch them, quite telling me how I HAVE TOO! I already have 4 or 5 shows I like to watch and anything more is just too much TV for me.
I also find that I have trouble watching any tv series after the 5th season. I guess I just get bored.