They were the ones who came to my mind immeadiately. They make great games that keep me thinking, and aren't a simple cakewalk. Nintendo takes second in today's market, though back in the SNES days, Enix (with Quintet) was first, and Square was 2nd. How the mighty have fallen...

Hmmmm probably Nintendo followed by Blizzard and Valve.

Honourable mentions to Bullfrog before they died.

Realy?

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.

Nintendo > Blizzard > Valve > Square before 2000 >>>>>>>>>>>>>>>>>>>>>>>> rest

Level 5 for sure (because of Layton, DQ IX and the future games for 3DS).

Then, not counting Nintendo because it's an unfair comparison, Capcom because of the Ace Attorney series (Shu Takumi FTW!). Also honourable mention to NCsoft because of Guild Wars.

Naughty Dog <3

Naughty Dog, by the fact they made Crash... work!. 

Quite a fan of Epic as well, pretty bloody impressive work that they make an engine and still make damn fun games. 

Bioware as well.

Rocksteady Studios simply for Batman Arkham Asylum. They went against the trend of games that have to made about the movie and made the game awesome. Not shit.

Valve... coz they are Valve, ID software... coz they are ID softwae

For me its a split between Valve and Bioware.

Game Freak, followed by Nintendo EAD.

Nothing can compare to Pokemon, obviously, and I don't see how a lot can be put on top of almost every other important Nintendo game.