I'll list companies I think are good:
CDPR - they listen to fans and critics while maintaining their own creative identity. Insanely ambitious and think outside the box. Their post release support is unparalleled: the amount of free shit they patched into TW1 and TW2 was fucking crazy. They don't cater to the mainstream. Might be the only AAA dev that embraces a DRM free policy.
Larian - HUGE fan of these guys after playing Divine Divinity, and their old school return in the latest iteration shows they value creative integrity over profit.
Egosoft - the only AAA dev still making Space sims. PC only developer. They have an excellent website with great support by the community and the devs. DRM free policy as well.
Klei - excellent PC port in MOTN.
Arkane - another dev devoted to PC. Dishonored on PC was flawless.
RockSteady - although GFWL was a mistake, one of the few remaining devs focusing on lengthy SP campaigns in the action/adventure genre. They pack their titles with an insane amount of content and their PC ports are polished.
Flying Wild Hog - former vets from CDPR and People Can Fly. Very experienced. DRM free policy. Excellent post release support. Listened to fans about complaints with Hard Reset and had it patched within a couple weeks. Hard Reset is the most well optimized game I own - they deliberately targeted mid-range PC's when designing their engine. Can't wait to see what they do next.
Friction - they made Amnesia: Dark Descent. It's like two blokes in Sweden, and they made fucking Amnesia.
Eidos Montreal - not many people thought they could do Deus Ex justice, but they did. Solid PC port. Released a lengthy DLC mission. Listened to fan feedback about the game and made the augmented site feature optional.
Black Forest - Gianna Sisters is DRM free and a solid game. Look forward to more from them. Coming to XBLive for those interested.
Triumph - Age of Wonders has a dedicated community with tons of fan made modules and it's DRM free. It's like the Star Craft of the fantasy genre, been around forever.