Sega AM-2 (AfterBurner, OutRun, Virtua Fighter, Daytona USA, Shenmue)

Sonic Team (from 1991-2001, after that they're garbage)

Clover

Treasure

lets see

Nintendo - for Mario, Zelda, Metroid etc etc
Blizzard - Warcraft, starcraft, Diablo, Wow, Lost Vikings
Capcom - Street Fighter, Mega-man
Bioware - for their numerous RPG's
Square - Final Fantasy, Dragon Quest
Insomniac - Ratchet, Resistance
ID - Wolfenstein, Doom, Quake
Valve - Half-life, Portal
and my personal favorite
Cavedog for bringing the world massive destruction with Total Annihilation.

Total Undisputed Winner: Nintendo EAD 3/ Where ever Shigeru goes
1.Capcom
2. SquareSoft - Why did they have to make that movie and bomb =(
3. Blizzard - they took 3 years of my life away with Diablo 2, WC3 combo
4. Tri-Ace
5. EA Big - Yea I still like SSX.. sue me
6. Atlus
7. Grass Hopper (No more heroes and thats it... so far.)
8. Someone goes here... but oh well I can't remember them all.