We tried Blockbuster a few years back. They were more expensive, but I loved that I could take the mail order movies back to the store, and trade them in for movies at the store at no charge, but still get the next movies in our queue through the mail.
I've never tried Netflix but definitely have been thinking about it here lately.
I've been with Netflix for over 5 yrs now and LOVE IT! It's the best system. You can keep the movies for as long as you want with no late fees~ no rushing out the door because "Oh darn it! Have to get that movie back before midnight!" sort of scenario.
They also have EXCELLENT customer service. The one time I dropped a movie back in the mail into a mailbox outside of a shopping plaza and it was one I never used before, the movie was late getting back. I notified them and they reflected it on my account and sent the next movie out immediately (since then I only return the movies at the post office~ that way it only takes a day, 2 at the most~ for them to receive it and get the next one sent to me!)
They also have it where you can watch movies directly on your computer as well as direct movies to your Wii system so there's no waiting for those movies to come in the mail!