After spending years completely ignoring television, I now semi-predictably watch episodes of House and Fringe. I think my main difficulty with TV is that I don't like having my entertainment bound by someone else's schedule. Even a DVR has its inconveniences (like, on the ones I've seen, that you can't watch a show while you're recording a different one). It'd be better, for me, to get the shows on DVD, but I'm not going to pick up TV shows when I could spend that same money and get the DVD of an actual movie.
So I suppose the short answer is: TV would have to be as good as movies.