Listmania!
The Best of XBox 360
By an Amazon.com customer
Gears of War 2Gears of War 2
Buy new: $36.99 / Used from: $17.98
If you like playing co-op with a friend and enjoy shooters, this is the best game for it.
Fight Night Round 3Fight Night Round 3
Buy new: $18.49 / Used from: $5.70
You don't have to typically like sports games to enjoy Fight Night. It's fun no matter who you are. And if you have friends, it's an excellent head-to-head experience.
Burnout RevengeBurnout Revenge
Buy new: $99.94 / Used from: $10.50
Racing games aren't my cup of tea but I love Burnout and I'm sure many racing fans enjoy it as well. It's extremely fast and intense. And what's better than slamming other cars (including your buddies) into guard rails and trees and bridges to watch them completely get obliterated in slow-mo!
Soul Calibur IVSoul Calibur IV
Buy new: $32.21 / Used from: $13.95
If you like fighting games this is the game for you. Lots of depth here for the hardcore fighting fan but caters well to casual players also.
Dead RisingDead Rising
Buy new: $19.49 / Used from: $9.94
If you're a Romero fan you have to play this. If running around a huge mall saving survivors (or not :P) by killing literally hundreds of zombies with weapons like skateboards and electric guitars sounds like a blast (and it is) this is the game for you.
Elder Scrolls IV: Oblivion Game of the Year EditionElder Scrolls IV: Oblivion Game of the Year Edition
Buy new: $27.49 / Used from: $18.38
This is the best RPG experience on the 360. Period. Fallout 3 and Mass Effect are great, but if you haven't played this yet, you should definitely grab it first.
Resident Evil 5Resident Evil 5
Buy new: $36.99 / Used from: $20.80
Another good zombie-type game but it plays quite differently from Dead Rising. This is another good choice if you like playing with a buddy because the whole game can be co-op whereas Dead Rising is only single player.
Call of Duty 4: Modern Warfare Game of the YearCall of Duty 4: Modern Warfare Game of the Year
Buy new: $44.99 / Used from: $28.00
If you have even the slightest interest in FPS games, war games, or anything that has to do with shooting bad guys, you MUST play this game. It's the best of the best hands down. It's not co-op but it's single player campaign is incredible and the deathmatch multiplayer is a blast too.
Call of Duty: World at WarCall of Duty: World at War
Buy new: $56.99 / Used from: $26.50
Again, if you enjoy FPS you MUST play this. The single player campaign wasn't quite as awesome in this one as it was in COD4 but the best part about this game is that you CAN play with a friend via co-op.
Saints Row 2Saints Row 2
Buy new: $29.99 / Used from: $18.72
Say what you will. I'll play Saints Row 1 and 2 any day before I'd play GTA IV again. I enjoyed them more. This is a blast playing with a friend. It's like Grand Theft Auto only it doesn't take itself so seriously. I laugh at the crude humor and ridiculous events that happen in it and I'd recommend it to anyone who isn't easily offended.
Dead SpaceDead Space
Buy new: $19.99 / Used from: $15.99
If you enjoy survival/horror, watching grotesque violence, and can't wait for the next good horror flick to come out, this is a good game for you to pick up. Plenty of thrills, lots of suspense, and lots of violence to top off a well-crafted game.
Tom Clancy's Rainbow Six Vegas 2Tom Clancy's Rainbow Six Vegas 2
Buy new: $19.99 / Used from: $10.53
Another great shooter to jump into with a friend or just by yourself. It requires a bit more strategy that your typical shooting games. And if you're sick of online deathmatch, give the 4 player co-op terrorist hunts a try. They're a blast!
BioShockBioShock
Buy new: $18.99 / Used from: $12.75
This is a great single player shooter. It can be a bit on the creepy side (in a good way if you like that sort of thing) and the gameplay is top-notch.
Mass EffectMass Effect
Buy new: $19.99 / Used from: $10.90
A good RPG that uses some shooter elements. If you enjoy sci-fi, good stories, or RPG games in general, give this one a go.
Fallout 3Fallout 3
Buy new: $36.99 / Used from: $21.97
This is an excellent RPG that uses shooter elements as well. Again, if you like apocalyptic sci-fi, good stories, or RPGs you should give this a shot. (Matter of fact, if you enjoyed Mass Effect you'll probably like this and vise versa).