While they've fallen from grace in a lot of eyes, I'm still going to go with Bioware. I've yet to play a game of theirs that I did not completely love.
Also...*sigh, I'm asking for a beating in this place but I'm going to have to say EA Sports. WHAT!?! Don't look at me like that! I've probably played my FIFA 12 and Madden 11 more often than most other games...what can I say, Tippy2k2 loves his sports games.
Here, if it helps get my Escapist street cred back, I'll put in Obsidian Entertainment down as well. While flawed, Alpha Protocol was a great game if you can see past all the hiccups. Knights of the Old Republic II is a classic. Fallout: NV was a blast and that new South Park game they are developing looks sweet. They are evidently (according to Wikipedia) developing a game based on The Wheel of Time series, which makes me cautiously excited.