FPS: Close tie between Half Life Opposing Force and Halo 2
JRPG: Very Close tie between Pokémon Sapphire and Pokémon Gold. (If that doesn't count, I guess Chrono Trigger)
WRPG: Fallout 3
Racing: Metropolis Street Racer
Fighter: Smash Bros Melee
Beat em' Up: The Warriors
Platform: Super Mario Land 2: Six Golden Coins
Stealth: Metal Gear Solid 2.
Shoot em' Up's: Space Invader's Extreme
Third Person Shooter: Saint's Row 2. (If it counts, if not, I am not sure)]
Action Adventure: Legend of Zelda: The Minish Cap
Visual Novel: Phoenix Wright: Ace Attoney
Interactive Movies: Heavy Rain
Real Time Strategy: Halo Wars
Turn Based Strategy: Fire Emblem: The Sacred Stones
Puzzle: Portal
All time favorite is The Legend of Zelda: The Minish Cap.
Anything else means you're a casual.