Nintendo!

Blizzard. There was a time the answer was Valve.

Platinum Games

I liked THQ, but now that they are gone it's probably Obsidian Entertainment. CD Projekt seems to be a good developer too, but i have not played one of the witcher games so far.

From software and level5

CD Projekt or The Fun Pimps

Square Enix

TaleWorlds Entertainment for Mount & Blade series. Yes.

View attached image.

XSeed or Squaresoft (NOT Square Enix)

Square Enix

Most of my favorite games are from Valve, but there is a special place in my heart for all BioWare RPGs - so BIOWARE FTW!!! (Also mario creators and blizz - because WARCRAFT!)

Key17, the one I work with...
Hope you don't mid I smuggle in a thanks anyway... O.o

atlus :)

Used to be blizzard before their always online policies.

Mojang. Best devs ever.

can't say that i have a favorite gaming company

I like many but nintendo has been with me for the most time!

None atm. They pretty much all decided to care about money 90% and customer 10% lately. While they all have games I like in their line-up, I still don't feel like picking a "favourite".

Paradox

Paradox ?

CCP

Avalanche! And I love most games released by Square Enix.

double fine!

There is a few, but I choose idSoftware.