Why aren't you guys using Gamefly? My copy should be here by Thursday. If you buy more than 4 games a year, gamefly is a great option. I pay 22 bucks a month and can have any two games out at a time for as long as I want.
In fact, just today I upgraded to the 3 game plan which is only 28/month. I have Madden and Dead Rising on the way to my house as I type!
I used to buy about 2 or 3 games a month, which at the current rate of 50-60 bucks each, gets costly in a hurry. Then after playing it for a month, I hardly ever play them again, but the trade in value is sh*t. So I went with gamefly and have been happy ever since. Plus I can get 360, Xbox, PS1/2, and GC games. I highly recommend it if you are a serious gamer.