Tie between Blizzard and Square Enix.
Blizzard has not put out a bad game since I started with them with Warcraft 2. I still have fond memories of Blackthorne.
Square Enix is equally as good because of their catalogue of games they could reboot any one of them and sell 2 to 10 million. Parasite Eve, Brave Fencer Musashi, Front Mission, Secret of Mana, Chrono Trigger, Terranigma, ActRaiser, SoulBlazer, EVO: The Search for Eden, Ogre Battle, Dragon Quest and on.
Square Enix with the catalogue of games they have today could survive a gaming crash on the proportion of the 1983 video game crash. Blizzard could too, but they would be hurt a bit more due to their marriage with Activision who always seems to take and rarely give.
BioWare is a very close second. Excellent catalogue of games and in a better position right now than Blizzard was in 1998.
