Inti Creates
Yacht Club Games
WayForward
InXile Entertainment
FrozenByte

I personally like usually japanese games more. But there are some western devs, that develop games I like. Ubisoft are hits and misses, some games are good, some not. As I like Borderlands, I have to say Gearbox. Bethesda creates pretty good games.

But the bestestest are without a doubt Larian Games, Obsidian and CD Project Red.

Blizzard
Rockstar North and San Diego
CDP Red
Bethesda and studios
Ubisoft Montreal or Ubisoft in general. Hit and miss but they keep trying and always stay creative...a very French feat.
Rocksteady

Bioware is dead, sadly, , like everything EA touches.

In terms of technology definitely Crytek and Epic for sure.

Also thanks for the guys bringing up indie studios...need to take a closer look.

And hell....how could I forget LARIAN?!! (Edit: Glad to see the one above me had the same thought, but yesss Obsidian deserves to be on there as well!)

Rockstar. Easy best dev team out there

Ok, I've left the thread alone long enough now. Keep in mind I said multiplatform devs, so if they haven't released a game for PC/XB1/PS4 then it doesn't count.  Here's my list...

1. Bethesda: Probably the most prolific 3rd party developer of this gen. They've released Doom, Prey, Wolfenstein, Dishonored, Fallout 4, and Skyrim this gen. 

2. CDPR: The Witcher 3 is a really good game. IMO best Non-Bethesda western RPG this gen. 

3. Rockstar: I'm a little worried about these guys. They seem to be delving into MTS territory. Hopefully RDR2 is good and free of MTS. 

4. Obsidian: Pillars of Eternity and South Park. Crystal Dynamics: Tomb Raider

5. Crystal Dynamics: Tomb Raider

6. Blizzard: Their only multiplatform game is Overwatch though. 

I made this thread, because I wanted to see exactly what was left for good 3rd party devs. IMO Bethesda and Rockstar are the only western devs that Nintendo needs on their side. Everyone else either sucks, or is only known for a single franchise. 

Well I didn't want to define it because I thought a lot of people might disagree but... 

How about any western 3rd party developer that consistently gets 80 or higher on metacritic, and doesn't include MTS (beyond cosmetics) in their games? So WB games, and EA aren't in the running. I don't care how good your game is. If you (or your publishing company) want to charge basically $100 for it, then you are not a developer whose games I look forward to. 

Blizzard are known for having multiple IP's under their belt, majority of them well known throughout the years they've been around.

The thread is titled "What are the best 3rd party multiplatform developers". In terms of multiplatform Blizzard is just known for Overwatch, and maybe Diablo III (If you want to count a last gen port) this gen. 

1. Square Enix the western branch
2. Bethesda
3. Rockstar

No one has mentioned the greatest western developer yet : Spanish studio Mercury Steam. Lords of shadow one and two are both unquestionable masterpieces, Clive barker's Jericho was also excellent. They also did raiders of the broken planet and Samus returns this gen. Getting them on board for the switch with an exclusive AAA horror fantasy title, perhaps eternal darkness 2, would fill one of the few gaps in the switch's library.

And Hearthstone, which covers multiple platforms and OS's. Some of Blizzard's titles also run on Apple's OS as well.