OK here's my advice
Go to screenselect and join up for your free months trial.
If you can't find a code I'll post one tonight for you.
Add loads of 360 games to your rentals list.
Games I have played:
Condemned - still freaks me out must find time to play it through. 10/10 for atmosphere.
KingKong - I hated this with a passion, kill it with fire (that's *** game summarised then). Was an easy peasy 1000 points though. Definately a rental. 4/10
Full Auto - I love it, I really like it, big yank cars with guns and bombs and mayhem. Not for the Michael Schumaker types but for ex van drivers and those of us prone to a spot of getting out the car to have a word with the guy who cut you up it rocks. 8/10
GUN - had it on rental, did not get to finish it. Really liked it. A sort of GTA western with hatchets. 8/10
CoD2 - the first game since Red Alert that I cba to finish. Brilliant a must play.9.5/10
Kameo - well..... it's quirky. Found myself strangely attracted to Kameos evil sister

I liked it, I even finished it but cba with getting all the achievements.9/10
Amped 3 - See my thread on that. Its snowboarding with lots of WTF! factor. Cba to get lesser or supreme snowgod achievements as it's a rental. If I owned it I'd get em all one day. I enjoyed it, kinda of relaxing and yet frustrating and very much a case of WTF SNOW SHARKS ?
7/10
Oblivion - I love this game. I really love it. But the time investment required is beyond me for now. 10/10
PGR3 - my first bit of OCUK online gaming back in december. Great fun online with a crowd. Singleplayer isn't really my thing with this - too much accuracy and too much of the same old thing. No guns. No bombs. No WTF!. 7/10
Other games I have yet to play but want to : tombraider legend, PDZ (own it yet to try it) GRAW.
Alternatives to renting include ....
Go to GAME and buy a 360 game, play for under 10 days and return it.
Always pay cash for this though and always get a cash refund.
Don't always return to the same branch.
try to return to the Game branch in the Marlowes in Hemel Hempstead and tell the manager there that you'll "see him after work". Leave before the police arrive.