netflix type companies for game rentals

The latest issue of play magazine had many advertisments for them. Basically if you have used netflix, you will know what it's about.

http://www.gamefly.com/play
http://www.triggerfingers.com (promo code: play)
http://www.deepshark.com/play
http://www.redoctane.com/
http://www.govojo.com/

I believe all of them have free trials, and all of them have pre paid envelopes for return. So you don't have to pay for shipping. Check them out if you are bored.