And regional pricing with The Witcher 2 (I think it was the first game with a regional lock, too). And you had to register on GOG to download a day 1 patch (needed to run the game!) for the boxed copies of The Witcher 3.

There are many, but wanted to add Revolution Software because like CD Projekt they are
extra nice.

No, freely available here from day 1: http://play.thewitcher.com/

I made a "Games that treat GOG customers as business class citizens" thread some time ago, you might find some titles there.
https://www.gog.com/forum/general/games_that_treat_gog_customers_as_business_class_citizens

Yup, you're right. It was the crapload of free DLC that was only available via GOG for owners of the retail copy. I mixed things up here. Doesn't change the fact though that CDPR "forced" people to use GOG.

Except for the months we had to wait until they finally fixed the missing controller prompts in Darksiders II which made the game - designed for a controller - almost unplayable. They did not have any problems to fix the Steam version though - unfortunately the versions weren't compatible so GOG users had to wait ... a lot. Not to mention that they removed the original Darksioders II completely instead of adding it as a bonus to GOG. Since the Deathinitive Edition is imperfect (to be friendly) it would be so great to have this as well.

Also Tom, the guy who announces new games here on GOG mostly just comes in saying "Enjoy" but in nearly all cases don't answer any questions people are posting in the same thread. So while I agree that it's great they bring so many games to GOG I would disagree in calling them first class devs - afaik Black Mirror also is still buggy btw. Then again they aren't devs, they are publishers so it's hard to include them anyways imo.

Several people (including myself) reported to them that Flashback has a wrong aspect ratio in the anniversary edition. I also added that the way they implemented the feature settings by having to be forced to chose between classic (all additional features "off" and remastered (all additional features "on" - which resets the settings you just did in the options screen) is suboptimal. Did not even get a reply - afaik nobody did. First class?

But I guess you would not mind them if they are optional (as they are in most cases since you won't see them without Galaxy and you can also turn them off if you use Galaxy. I do agree that some kind of achievements that cannot be turned off at all (mostly in game achievements) could be distracting though.

I heard the same but it was just from another guy and no official source.

Yes, I hate Achievement popups in games. "You got some meaningless 'reward' for playing the game" messages always break the immersion. Achievements are OK as long as they are silently tallied in the background, where they can be ignored. But as soon as they cause any in-game messages, they become annoying.

Not all. For example, they promised a Linux version of Battle Chasers: Nightwar over a year ago, and delivered one to Steam over 6 months ago. gog users get nothing. You should check the 2nd class citizen list before making such claims.

Shoutout to Image & Form games for starting day one releases on GOG with Steamworld Dig 2. I hope they continue the path, and I'm really rooting for a Steamworld Heist 2.

Shoutout to Ron Gilbert and his microscopic team for giving this platform their time and trust. Ron has released recent revenue statistics of Thimbleweed Park, and GOG has an impressive percentage – though of course GOG seems to be the last distributor to even pay out the quarterly revenue to devs, which makes his commitment all the more impressive.

Shoutout to Double Fine for eventually giving GOG keys of Broken Age to their backers, which they had never promised but still eventually rendered, just because they could.

They're new, but so far the devs of Monster Prom have been good. Though it was on Steam a while before it came to GOG, since it did come, it's been getting same-day updates as on Steam, including the "free DLC" winter update. I had positive emails when I had emailed them midsummer asking them if they would look into GOG. The game's multiplayer is even cross-platform between GOG and Steam [so they say]!

Double Fine refuses multiplayer support for Brütal Legend though here on GOG, while Steam does have it.
So no, Double Fine treats GoG customers as second class citizens.
See also the well-known post about it
https://www.gog.com/forum/general/games_that_treat_gog_customers_as_second_class_citizens_v2

Thanks all for posting which devs and games are great !

I am going to post a reminder here that this thread is for shout-outs, let's stay focused on who and what is really great. This is not about whose taste in games is best, nor a place to argue, but to point out the hardworking devs who you think really turn out a great game experience and support. (Though the point about a dev not publishing new coop feature on gog but doing it on steam version caused me to add that type of thing to the OP as an edit.) The responses for shout-outs have been very interesting.

The Shout-out focus is:
Devs who make their game a comprehensive positive experience, because of their overall product quality (software, design, operations, etc.) plus their ongoing support in product maintenance and development, their positive involvement and attitude with the customer/community, informative support such as website, and game specific forum with dev participating as needed. The guys who really nail it.

Xseed , has many games here that have gog galaxy support , they update their games fast and also sometimes they are answering questions on the forum.