Of that list I would say Bethesda just do to the amount of time I spent playing Oblivion, Morrowind, and fallout3
Bioware is a good developer but I don't like the you can only be really good or really evil system that they put in all their games, and it doesn't matter if you chose really good or evil as the game plays out the same but with different cut scenes
Valve is another good one, but I don't like how they think charging $20+ for 2hr games is alright.
I used to love nintendo but now all they care about is junk like Wii Fit