One of the best things about our NETFLIX membership is that there's a good number of TV series you can see anytime you want through this service. We get the subscription for a single movie at a time, but even that gives us unlimited access to the selection that is available over the internet.
We bought the ROKU player from them for a hundred bucks, but you can also use a PS3 or XBox to view them on TV. If you are considering a Blu-Ray player, some of them have the capacity to stream Netflix to your TV as well. Wal-Mart has a Blu-Ray right now for $150 bucks that will do that, and I wish we'd known about it before we got the Roku, as it would have killed two birds with one stone (and saved us about $50). What's more, Pat has PS3 at school, so he can watch movies there on our account (I don't know if that's an intentional feature, but he's been doing it for over a year and we've not been told to stop it yet.).
Among the series we revisit or play catch up on:
Buffy- the ENTIRE series
Angel- the ENTIRE series
Dr. Who- selected storylines for Doctors 1-7 and the ENTIRE series 9 and 10
Spartacus: Blood and Sand- this becomes available the day the episode airs on STARZ
Dollhouse- Haven't watched it yet, but the ENTIRE series is available
Firefly- the ENTIRE series
Sanctuary- Season 1
Xena- the ENTIRE series
Hercules- the ENTIRE series
Primeval- the ENTIRE series
Torchwood- the ENTIRE series
LOST- Seasons 1-5
Dresden Files-the ENTIRE series
Various MST3K episodes
And many more, both genre and otherwise.
Truth to tell, any more we're paying for the service more for online function than for the DVDs.