I'm in love with my Amazon Prime account, although you would have to hook your computer up to your TV. Episodes of the most highly-rated shows cost the same as they do on iTunes, but some popular, less publicized shows (like Downton Abbey) are free. The free two-day shipping is a huge plus!
You can get a Roku box and not have to hook your PC up to your TV. The Roku boxes are pretty cheap, have no service fees and you can stream Netflix and Amazon, Pandora and some other random things to your TV directly from your router. We've got a few of them around the house, they are great.
It depends what you watch. I live Indie, foreign, and horror movies. They are all streaming all the time and I can see thingas I could never find at a local video store or Redbox. If you like big blockbuster Hollywood movies and don't watch that much- you're probably better off at RedBox.
I am kind of ashamed to admit that I also have an Amazon Prime membership, purchased for the free shipping and the Kindle lending library, and I didn't realize there was streaming content available.
I had better go check that out!
We have a Roku player hooked to our TV and have Nexflix (streaming only), Hulu Plus, our Amazon prime and our mlb.tv accounts available. I prefer watching tv shows on Netflix because there aren't any commercials, but they don't have the most recent seasons of the shows I watch. So I watch recent episodes on Hulu and baseball games on mlb.tv. I really like being able to watch my favorite tv shows with limited or no commercials whenever I want.
I have streaming only and I love it. Like others have said, the tv series selections are better than the movie selections. I tend to like British television series, and have been pleased with my subscription. Last complete one I watched was MI-5.
We have Netflix streaming as well. It is great for starting a show (Grey's Anatomy, Numb3rs, Private Practice for example that is on season 7 or so on TV that you want to catch up on. As others said, not super great movies.
I have streaming, and I also get one DVD at a time. So depending on how fast I watch & send back, I can go through several movies a month. Usually that doesn't happen and I go through 2 or 3, but I think it's definitely worth it.
Whatever I can't watch on live stream, I just get on DVD; these are mainly movies since most TV shows are live stream.