Naughty Dog - The Last of Us and Uncharted
Retro Studios - Metroid Prime and Donkey Kong Country. Also Mario Kart 7 if you want to consider 3DS
Bethesda - Oblivion, Skyrim, and Fallout 3
Bungie - Halo 3, ODST, and Reach. Still arguably the best FPS after a decade.
Turn 10 - Best rated racing series this generation with Forza
Epic Games - Gears of War, Unreal Tournament 3, Shadow Complex, Infinity Blade, and Bulletstorm. Kickstarted the 7th gen with Gears as well as having the most popular engine. Unreal Engine.
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Infinity Ward - Call of Duty 4, Modern Warfare 2, Modern Warfare 3. Redifined the FPS genre and have went on to selling well beyond 50m copies.
Valve - Left 4 Dead ,Portal, Dota, Half-Life
Rockstar - GTA, Red Dead Redemption, LA Noire, Max Paine
Bioware - Mass Effect, Dragon Age, Star Wars.
Not in any specific order. And im sure i missed plenty as well.
