Favorite video game developer?

Atlus and not just for Persona I've been a fan of everything they've made.

I am a Bungie fanboy. I will not deny it. Shiska gave me a hug.

Rockstar Games. Normally I'd probably go with Nintendo, but I feel they've really been slipping the last few years. Rockstar remains consistently strong and continues to push the boundaries of gaming.

ID software, Valve, and Blizzard. 
 
Epic Games would be a close second-tier.

Nintendo: Obvious reasons
Capcom: Some great classics
Square: Nothing better than a square RPG. 
Rare: Old-School though. DKC and Goldeneye FTMFW

Valve and Insomniac.. Im a sucker for Ratchet and Clank :)