LucasArts (Monkey Island 1-3, Grim Fandango, Full Throttle, Maniac Mansion: Day of the Tentacle, Indiana Jones and the Fate of Atlantis, Star Wars: X-Wing vs. TIE Fighter)

Westwood Studios (Dune II, Legend of Kyrandia 1-3, Lands of Lore, Blade Runner, Command & Conquer)

Great idea

A few rare exceptions of these I haven't played and included because they made the platform better.

Rareware: Perfect Dark, Conker's BFD, Banjo Kazooie, Diddy Kong Racing, Killer Instinct Gold, just so many great memories.

Hal Laboratory: Smash Bros 64, Smash Bros Melee, Kirby's Dreamland, Kirby's Adventure

Capcom: Megaman, Street Fighter, Zelda OoA

Konami/Ultra games: Castlevania, some great NES games.

Sega: Sonic Adventure, Ecco the Dolphin, Shenmue, Virtua Fighter 3

Nintendo R&D1: Metroid, Super Metroid, Mario Land, Dr. Mario, Tetris, Duck Hunt, Mario Bros., Donkey Kong.

Nintendo R&D3: Punch-Out!!

Nintendo EAD: The Legend of Zelda, Super Mario., F-Zero, SimCity, Pilotwings, Nintendogs, Mario Kart, Pikmin, Wii Series

Factor 5: Rogue Leader

Lucas Arts: Tie Fighter

Ubisoft Montreal: Prince of Persia

Retro Studios: Metroid Prime

Team Ico: Ico, Shadow of the Colossus

Naughty Dog: Uncharted: Drake's Fortune

Blizzard: Warcraft II, Diablo, Starcraft, Diablo II, Warcraft III, Starcraft II, Diablo III

Squaresoft: Final Fantasy

Tecmo: Ninja Gaiden (NES Classics)

Neversoft: Tony Hawk's Pro Skater

Sierra: King's Quest, Space Quest, Jones in the fast lane.

Nintendo, Retro studios, Squarenix and old Rareware
simply put they made the games ive enjoyed most

Nintendo EADs (all)

Retro Studious (Metroid Prime series; DKC:R)

Monolith Soft (Baten Kaitos 1 & Origins; Xenoblade)

iNiS (Ouendan)

Mistwalker (Lost Odyssey; The Last Story)

From Software (Dark Souls)

Jupiter (The World Ends With You)

Brownie Brown (Magical Starsign; Heroes of Mana; Mother 3; Sword of Mana)

Renegade Kids (Dementium 1 & 2; Mutant Mudds)

Tri-Ace (Valkyrie Profile; Resonance of Fate)

Tri-Crescendo (Fragile Dreams: Farewell Ruins of the Moon)

DICE (Mirror's Edge)

Sora (Super Smash Bros.)

etc...

In no particular order:

1.) Valve

2.) Bethesda

3.) Maxis

4.) Sucker Punch

5.) BioWare

6.) Naughty Dog

7.) Rare (when it was in its prime, anyway)

8.) Bungie

9.) Rockstar North

10.) Ubisoft Montreal

It is nice to see so many people liking Bioware

And those who don´t, we´ll convince them

That's quite an interesting one.  I love Sucker Punch too, but that's pretty high up your list!  Any particular reason?  Huge fan of Sly and Infamous? :)

To all the people who have said DICE, a quick question: Are you a fan of their continued work on the Battlefield series, or do you follow all their other projects too? (i.e. Mirror's Edge)

Now there's a couple of really interesting ones as well.  Are you still a fan of LucasArts' current work?

I must admit, I forgot about Westwood when making my list.  Although I only ever played the Command & Conquer games, they took up a great deal of my time growing up.  Tiberian Sun was always my favourite!

No, not at all. Their last masterpiece (developed in-house, i.e. not Knights of the Old Republic which was only published by LA but developed by another great, well-known studio) was Grim Fandango, one of the best adventure games ever. That's 14 years ago.

Today I only care for their revived IPs (Sam & Max, Monkey Island at Telltale) and former employees (Tim Schafer, Ron Gilbert at Double Fine, Dave Grossman at Telltale, Bill Tiller solo).

As for Westwood: I absolutely loved Dune II (still my favorite RTS game today), Kyrandia 1+2 and Lands of Lore 1. More than C&C 1 which was a very good game as well.

By the way: My # 3 to 5 would be
- MicroProse (mainly due to Civ I+II - two of my all-time favorites - but also due to Pirates, Railroad Tycoon and others; or in short: due to Sid Meier)
- Bullfrog (Dungeon Keeper 1+2, Syndicate, plus the brilliant, today widely forgotten 3D masterpiece Magic Carpet)
- Ensemble (only at #5 because they just had one franchise with two outstanding RTS games; great, but somewhat slow an lazy studio)

Blizzard doesn't make my list because WarCraft was the only of their franchises I ever liked. They were way more productive than Ensemble (which payed off greatly as they rule the west today plus a certain part of the east, while Ensemble are defunct) but I never cared about Diablo, StarCraft or WoW.