Are you working on a television show script for one of those contests that makes you write a script from a show that is currently on the air? If so, you might want to check out Fancast as a resource for your TV shows.
I have not had a lot of time to check it out myself yet, but there are a lot of TV shows on there for free. And they have full episodes of these shows too. However, it does not appear that every network is taking part in this. But this might prevent you from having to buy dvds of a show that you might be writing a script for. And at a minimum it is a great way to watch your fave TV shows for free online.