I'd have to say DICE since BF3 is coming out tomorrow and is going to be awesome. Valve is great, and 2k is pretty good mainly for Bioschock.
The problem I have here is that I see a lot of people saying Activision. Let me just remind you that Activision is not a game developer, they are a publisher thus they don't make the games. If they have concepts for a game they send it to a studio. When the game is ready they take care of packaging, distribution, and marketing.
I could go on about the conglomerates of EA and Activision, but you can find that for yourself if you'd like to educate yourself further than being the guy who buys everything they're selling just for the name.
I HAVE THE ANSWER TO THE QUESTION YOU HAVE ASKED... THESE COMPANIES WOULD BE(RATED 1 BEING BEST) 1.ACTIVISION... GUITAR HERO 2.THE GUYS WHO MADE COD SERIES 3.TIE BETWEEN BUNGIE(HALO SERIES)AND BLIZZARD 4.TIE BETWEEN VALVE AND UBISOFT 5.EA GAMES...NEED FOR SPEED SERIES 6.SONY...GOD OF WAR SERIES
Nintendo. Best games since the 1880s! Check it out. Nintendo goes back into the 19th century. search "nintendo History" and click on the Wikipedia link. They made cards at first, then 1970s simple video game systems. then BOOM 1980s with the NES!
3. Valve: From the hilarious puzzles of Portal to the teamwork based L4D series, Valve has yet to make a bad game. It may not be the oldest company, but it's meant for greatness.
2. Capcom: Besides revolutionizing the fighting game genre with Street Fighter (As well as taking on other popular companies in fist fights), Capcom also has a niche for zombies with Dead Rising and Resident Evil. Then throw in a mascot who is only 2nd to Mario in number of titles, Mega Man, and you get a very well-rounded and professional developer.
1. Nintendo: Let's see...Super Mario Bros., Legend of Zelda, Metroid, Donkey Kong Country, Kirby Super Star, Pokemon Gold/Silver/Crystal, all of these are many classic titles that are a part of an endless rotation of series releases. Besides those classics, they also have Super Mario Galaxy 2, Metroid Prime 3: Corruption, Legend of Zelda: Twilight Princess, Donkey Kong Country Returns, Pokemon Black/White, and Kirby's Epic Yarn. They may not be for hardcore, masochist gamers, but they give a nice feel of nostalgia and still manage to stay on top with newer, more innovative releases each year.
1. Capcom[Devil May Cry 1, 3&4] 2. Bio-f'in-Ware for their MASS EFFECT. it's perfect 3. Square Enix [Final Fantasy series] [played Infinite Undiscovery didn't like it. it has a good intro but everything was either slow to develop or either too fast that you didn't have any chance to savor the development. nice ending though. ] 4. EA [Battlefield] I like shooting games but I like it better if you play it with COORDINATION and COOPERATION. I like COD:MW too but you play it with no teamplay, so Battlefield wins in my book.