Not TV per se, just a movie. I put the movie on my desktop, and write on the laptop. Normally, it's a fluffy fantasy movie (Like, A Knight's Tale, Eragon, Princess Bride) anything that can just be settled into background noise. I used to write to music, and still do, occasionally, but I find myself always wanting to get up and dance/sing along if I do. So, the movies work a little better.

Plus, they get my fannish brain going which kicks over to the original fiction part of my brain and I get new ideas/new lease on brain power.