All three of mine have a tv in their room.
The boys share a room and have it hooked up to cable with a DVD player. They are only allowed to watch in on weekends or school breaks. They do not try to sneak it on, etc, they are actually very good with the rules.
Our daughter has a Dora tv/dvd combo that we do not have hooked up to cable yet. She is only 4 so, we are waiting until she gets a little older to do that. She does watch movies if she is not feeling well or on school breaks, etc.
My kids are actually not big TV fans. My oldest watched the Kids Choice awards last week. My middle guy will watch the Yankee game once and awhile in his bedroom and my daughter hardly ever watches it.