Like 3D, multiple classes, plethora of skills checks and customization and newer.

Not:
Dragon Age series
not pathfinder nor pillars
not witcher series
not dark souls
no divinity series
no drakensang series

but multiplayer or jrpgs are fine.
Or roguelikes, just no shooters.

nothing is acceptable answer

Drakensang series. Not the browser game though, i'm talking about the cRPGs.

Thank you, forgot I have those.

Kinda sounds like you already know all the big RPGs and are desperately hoping there's one you overlooked (even though I think you've created similar threads in the past?). So I doubt anything I post will be news to you, but here goes:

- Drakensang: The River of Time (not that new anymore, and I don't remember that much customization, but it's pretty close to NWN2 otherwise, except that it's The Dark Eye, not D&D
- The Elder Scrolls games (you probably forgot to list them under "not" ;) )
- other games you might have forgotten when you wrote no Pathfinder or Pillars: Tyranny, Torment: Tides of Numenera
- Dragon's Dogma (I think it's been suggested to you before, too)

Jade Empire, The Witcher

Yeah, I have all those.
Just wanted to see if I overlooked something new.

Two Worlds & Two Worlds 2
Torchlight & Torchlight 2
Diablo + Hellfire

Well, there are some upcoming ones, like:

- Iron Danger
- Realms Beyond: Ashes of the Fallen
- The Waylanders
- Black Geyser: Couriers of Darkness
- Encased: A Sci-Fi Postapocalyptic RPG

but I don't know much about them and whether they will be released on GOG or not.

Zenith perhaps, though its not really a complicated game.

I also recommend looking for Inquisitor, which is like a semi-diablo like.

There is also the rather unknown Hack and Slash game called Throne of Darkness.

I highly recommend Sacred: Gold, which probably ticks all of the things you want to experience. Be aware that this game has a weird graphics bug which makes you see the refresh rate on screen since it flickers weird but I'm sure there was a fix for that, hit me up via PM if you're interested.

Alright then it doesn't really fit here and you can skip this one :)! Its just that I thought it would fit because I played it for a few hours but I understand that it might not belong as a proper recommendation. There was a reason I mentioned it first because I wasn't sure myself. The other entries should fit into BeatriceElysias description however.

These don't fill all your criteria, but if you've not checked them out, they may be worth a look:

Elex
Risen series
Gothic series

Only ones I can think of that haven't been mentioned.

Kingdom Come: Deliverance
Vampire the Masquerade - Redemption

Arguably, Dragon Wars fits many of your criteria:

As for how well it fits, here is the lowdown:
* 3d: The main view is a first-person perspective 3D view.
* Classes: There actually aren't any; rather, the game uses a classless skill point system.
* Skill checks: Plenty of them here.
* Customization: Again, classless system with skill points, which can be spent as you wish. (But note that leveling is slow, so the majority of skill points you get are the ones you start with.)
* Newer: Does fail this, unfortunately.

I hate them myself, but it seems that Fallout 3 and NV would fit your requirements. No classes per se, but you can emphasize some skills over others to effectively change your "class". Neither fits the "newer" requirement, though. I guess you could get Fallout 4 or 76 on Steam. From what I've seen, they're even more like shooters rather than RPGs than 3 and NV, though. Plus Fallout 76 offends me deeply, with its cavalier attitude about slinging nukes.

I'm not sure why people are suggesting pure ARPGs, since they tend to avoid "skill checks".