The lights are on
For a gamer into FPS myself, try Left 4 Dead, great if you want achievements, but only a rental to myself if otherwise, versus really wasn't all that great, but the campaign was actually pretty cool, survival is a hit or miss.
Call of Duty 4 is still a great FPS, still some glitches, but has been fairly cleaned up since its release, and I find it still more fun than Call of Duty World at War, especially there being no tanks in any maps of multiplayer that you can drive, or get shot by. Just straight up killing with guns and explosives.
Battlefield Combat 2 was a great game for PS2, not so much when it made the leap to the 360, not much of support either than what the PS2 had online, more players I mean, I made the jump and there were some but not as much as what PS2 version had, so I might only suggest it for a few hours, but a solid rental still.
Rainbow Six Vegas 1 or 2, both great but still I find vegas 1 certainly more challenging, but in vegas 2 you can run, which makes it a little better to make up for the bad enemy AI. Both are a great buy at only $10 and $30 new. You might want to check them out, with fantastic player support either way you see them, I still have plenty friends on either one.
(if you would like to know about other games, I have close to 100 Xbox 360 games, so feel free to ask myself, I can't list off every game)
Thank You! :) Feel free to send a Private Message on here or the 360, or an e-mail to ask about anything.