Bioware.

I hate oblivion and I love Mass Effect.

OBJECTION!!!!!!!!:p
Square Enix!No matter the consoles,Square games are soooo killer!!

as much as i enjoy biowares stories bethesdas wrpgs are waaayyy better imo since your free to pretty much do whatever you want (including skip the story entirely so it doesnt matter so much that compared to bioware their stories arent as immersive and cinematic) bioware has side missions and such but their games are pretty streamlined and straight forward in comparison and i love freedom and custimization. with the exception of mass effect i feel the combat in the 2 newer elder scrolls as well as fallout 3 are better than bioware games. oh also forgot to mention slder scrolls games last FOREVER! ive had morrowind for i cant even count the number of years and still havent done close to everything in it, i havent even played the story yet. but either way theyre my 2nd and 3rd favorite developers behind only RARE (goldeneye + perfect dark > breathing) and ill continue to enjoy both of their games for years to come.
oh and lastly what makes bethesda better than bioware? umbra. that is all.

You forgot a major RPG developed by Bethesda...but I cant think of the name of it *cough* *Morrowind* *cough* *cough*

You mean The Elder Scrolls III: Morrowind? Yeah.... think about it a bit.

way bioware :p

If you held a gun to me, I'd say BioWare, but I like them both. I do think people tend to downplay how impressive the size of Bethesda games are, but I really enjoy BioWare's storytelling and they appear to have put more focus on exploration in Dragon Age than in Mass Effect.