@josejfernandez @kkarhan @rm4 @ErikUden
Yeah, aside from #GOG being probably the most prominent #DRMfree #videogame store, there's #itch.io (#itchio), which I think is mostly DRM-free. The only #DRM I've seen on itch has been devs selling #Steam keys (usually alongside but sometimes without standalone installers/archives).
Other stores include: #HumbleStore and #GamersGate, where DRM-free products are clearly marked as such. GamersGate is less likely but can be worth the extra click to check if you're already looking up a game on IsThereAnyDeal.
There's also #DLsite (for mostly Japanese games), which from my experience seems to be DRM-free unless otherwise indicated, though products with DRM on DLsite are a lot more common than on itch. (Also be aware that some products have English and Japanese versions or Windows and Mac versions sold separately.)
For #VisualNovels, #JAST (a.k.a. #JASTUSA) and #MangaGamer (NSFW warning for these sites, as you might expect) are both DRM-free.
Sometimes you can find publishers that offer DRM-free stuff on their own web stores. #FruitbatFactory does, for example. (I think Sekai Project and NekoNyanSoft also do but I've never used them before.)
As I understand, #BOOTH.pm (#BoothPM), #FireFlowerGames, #GameJolt and #ZOOMPlatform (the game store, not to be confused with the videoconferencing thing) also sell games DRM-free, but I've never yet used them.
FYI some of these aren't on IsThereAnyDeal (which already seems to have enough trouble sorting the large numbers of itch and Steam games). But there aren't that many to check. The biggest store that's missing is DLsite, I think?
(Sadly, the #Desura and #Playism game stores no longer exist.)