1. Mass Effect 2
No surprise here. This really is a must play for anyone who is interested in games.
Honestly, I didn't expect this game to be here. It was REALLY good. If you haven't played it you really should.
It's really a classic example of something that is greater than the sum of its parts. There's aspects, and mechanics from many different games (the most obvious being God of War, and Zelda) that if you were to read them on the design doc it would sound trite and derivative. But it really comes together to form a really good game.
Shits crazy son. Also the gameplay is second to none.