Adventure - Kings Quest 1. It was the first 3D graphical adventure, and more or less coagulated the basic gameplay formula that most all adventures today use, barring Myst and it\'s clones.
RPG - DragonWarrior 1/Final Fantasy 1. They created the core gameplay standard which would most CRPG\'s would follow on Consoles for years to come.
First Person Shooters - Wolfenstein 3D. Granted, Doom was the better game and far more recognised, but it\'s roots and core came directly from this precursor. If I\'m not mistaken, it was the FIRST true 3D FPS.
Fighters - Street Fighter II. Do I even need to say why?
Action - Not sure.
Sports - No opinion
Racing - Pole Position
Simulation - Not sure, Probably that Chuck Yegar flight sim. Special props go to A10 Tank Killer in my book for being the first Flight Sim to accurately portray the A10\'s usefulness in combat. Most sims which feature the A10 end up portraying it as the weakest of the planes avalable. However, the games engine is set up to accomdate dogfighters.. which the A10 is not... it\'s role is ground support for tanks, infantry, and disabling SAM launchers which endanger high altitude jets.
Platform - Super Mario Bros/Donkey Kong. Either or, Mario still ends up being the foundation cornerstone of the platform market we enjoy today.