Older game help!

I got a XBOX 360 for christmas so i have only had it for like 4 months and i know about present and up coming games, so i was wondering what older games should i check out and need for my library?

i like any type of game and play anything so im open to any and all suggestions. so what do i need to get?

Gotta try Lost Planet or Lost Planet Colonies, which is essentially the same game but improved and expanded on the multiplayer side of it.........awesome game online.

Its an old game but still has a huge following.

http://www.r3match.com/viewprofile.php?profile_id=6785

http://profile.gamebattles.com/jtek_maoriboy/

1. Halo 3
2. Gears of War
3. BioShock
4. Enchanted Arms
5. Eternal Sonata
6. DiRT
7. Condemned: Criminal Origins
8. Crackdown
9. Dead or Alive 4
10. Rainbow Six: Vegas