yoman3

What do you think are the best games in their respected genres? I'm not talking about YOUR personal favorite FPS or RPG, I'm talking about the 'best'. Meaning it is amazing in every sense of the word. I don't care if Halo 3 is your favorite FPS, that answer is wrong.
Also it can be a series, a specific game, or even multiple games. Also I'm just putting up nominations, none of this is definitive.

FPS:
Team Fortress 2
Half-Life
Half-Life 2

RPG:
World of Warcraft
Fallout 3

RTS:
Age of Empire series

Strategy:
Total War series

Puzzle:
Tetris

Stealth:
Metal Gear Solid series

Sandbox:
Fallout 3
GTA series

Adventure:


Action:

3rd Person Shooter:
Gears of War series

Simulation:
The Sims
Roller Coaster Tycoon

Music Sim:
Rock Band 2

Obviously there's a shit load more genres out there, but list your 'definitive' list.