Best game developers of ALL time?

[S.Peelman]

Nintendo EAD of all-time for Mario and Zelda among others
Naughty Dog during the PS1 and PS3 eras for Crash Bandicoot and Uncharted
RARE during the SNES and N64 eras for Donkey Kong, Banjo and GoldenEye among others
Ensemble during the 5th and 6th Gen PC equivalents for Age of Empires and Age of Mythology
Blizzard of all-time for Warcraft and Diablo
Creative Assembly of all-time for the Total War series
Maxis before EA meddled too much in their game design (so until SC4) for SimCity
LucasArts until the late 6th Gen PC equivalent for their Star Wars games and early original games

And the lesser gods

BioWare for Star Wars Knights of the Old Republic
Sony Computer Entertainment for MediEvil and Kula World
Bullfrog for Theme Hospital
Chris Sawyer for RollerCoaster Tycoon

This may be surprising, but yes, those are a lot of PC developers.