Atlus.
The, main, MegaTen series alone is praise worthy...never mind the offshoots.
Square-Soft.
Remember when they were still Soft? Used to have some real good stuff.
Treasure.
They managed to get me to enjoy a 'Bleach' (anime) game, so I'd have to say they rank up there.
Team Ico.
Two games, but so bloody good.
Interplay.
Fallout...even 'Run Like Hell' (which helped to kill them) was a decent game.
Sega/Nintendo/Sony.
Back when they used to make so stellar games. Sega is half-dead, Nintendo is a hit/miss, and Sony...when is the last time Sony made a game (or am I just not following them?).