Started out with Netflix, changed to Blockbuster and then after 3 months went back to Netflix.
If I return my three movies on Monday I have never had a problem getting movies from my que by Fri, which gives me enough time to watch those three and mail again the following Mon.
I also found that Netflix had a much larger variety of movies to choose from. In addition, it seems that the database they use to track my ratings and make suggestions if pretty darn good.
Overall rating...I more than get my monies worth with Netflix. I've only had one movie in the 2 years I have subscribed that I had to return due to an unreadable disc, outstanding delivery service for me, and excellent selection on the unusual movie selections I make.