For those who live in Canada (or Ontario, at least, not sue about other provinces) Blockbuster Video has a great deal for game rentals where you pay $30 a month (it comes right out of your bank account) and you can rent unlimited games. You can only have one out at a time (but they have another offer that you pay $40 a month to have 2 games out at a time) but it is so worth it when you're a gamer.
For those who don't know, the cost of renting games is about $10. I have had my Gamer's Pass (that's what this offer is) for two weeks and I have already rented 4 games so I already have more than my money's worth.
All you have to do when you return your game is take it into the store with you, pick out your next game, walk up to the cash and tell them which game you are returning and which one you are taking out. No Blockbuster card required (except for the first game you rent when you start the program) and there is NO DUE DATE on the games. You just bring it back whenever you feel like it. Finish a game in 5 minutes? Bring it right back and get another one. You can also cancel anytime you want.
It's like heaven.