I would say the likes of say Lucasarts or Bungie. But both studios have kinda disappointed me. Bungie made Halo Reach which IMO has really sub-par compared to the other Halo games. Lucasarts developed a good game on their own in well...forever.
But I have absolute blind faith in
Valve. Half-Life, Portal, and Left 4 Dead rules all. Day of Defeat and Counter-Strike are just nice bonuses.
Some others are:
Naughty Dog - Crash Bandicoot, Jak and Daxter, and Uncharted are games I will continue to love and play again and again. I have a Crash marathon of the first four games at least once a year to this day. Can't wait for the Last of Us!
Insomniac - Its hard to believe at one time I was a "Xbox" fanboy(Original Xbox FTW Underrated and Under-appreciated) as I started in the PS1 days. Spyro is amazing. Ratchet and Clank is mindless fun, and Resistance is a classic shooter with none of the nonsense in modern FPS games. I like the classic stlyle.
Id Software - DOOM, Wolfenstein, Quake, and now RAGE...enough said.
Raven Software - The best thing at Activision, they have created some of my most memorable gaming experiences. Both X-Men Legends and Marvel Ultimate Alliance(not the second one and it shows), Jedi Outcast and Academy, Quake 4, and much more. I think they had a few layoffs a while back so I don't know if the quality of the company remains.
Rockstar - I'm not fan of Manhunt or Bully, but you can usually always expect quality from Rockstar games.
Gearbox - Opposing Force, Brothers in Arms, Borderlands, AND bringing the Duke himself back from the dead! Go Gearbox!
Bethesda - The first game of theirs I ever played was Morrowind, while playing I kept thinking "why do I need to play another game again, this game is its own world I could spend a lifetime in!" Bethesda's games are usually like that, as developers or publishers you can usually expect quality.
Bioware - Dragon Age, KOTOR, and Mass Effect. I'd play Sonic Chronicles if it didn't require the stylus...
I'd like to mention many more (like Acclaim, Interplay, Nintendo, Eidos, Volition), but they haven't always had a good track record if you get what I mean. I'd like to also mention
Ubisoft but they are so large its hard to tell what they developed. But I love Prince of Persia, Ghost Recon, Splinter Cell, Rainbow Six, Rayman, FarCry, Beyond Good & Evil, and the awesome King Kong movie tie-in.
