Take a look at the D&D Gold Box games.

Have you tried the Witcher games. They are pretty good.
Also I have enjoyed the Mount and Blade game GOG gave away, so I think the series will be good too.

Psychonauts. Doesn't matter if you like the genre (I don't), doesn't matter what your preferences are, go play it.

I support wpegg wholeheartedly.
Play Psychonauts.

I would recommend Gothic 2 Gold.

¿Have you played Fallout 1 or 2? According to your collection, I get the idea that you seem to enjoy isometric RPG games on the action side of things. On that vein, I'd also recommend Arcanum wholeheartedly.

Something great and modern on that line would be Tyranny, and I don't have any idea why I also feel compelled to recommend here Hollow Knight even if it's an action platformer and has nothing to do with all this.

getpillarsofeternity. youllloveit.

Two games which have amazed ma lately so I can recommend: Darkest Dungeon and Darkwood. :)

How about first person rpgs? Heck, I need to replay this as well - it's most likely my favorite dungeon crawler. It all fits - the casting system, the story, the dread, the humor.

Please tell. Have it, but haven't played it yet :-)

Mount and Blade is the ultimate medieval simulator and RPG. The amount of mods for it is just amazing, you can really find anything you want from fantasy, to sci fi, to historical (American revolution).

You can find all the mods for each M&B version on this site: https://mountandblade-mods.net/

You should then! It's easy to learn but gives so many great feelings on different levels. The sound layer is one the most intriguing I've heard so far. Every survived night makes me so proud (and relieved). :D

That sounds a bit like Dying Light... (at least before you become level up A LOT).

Sacred 2

This can be played in first or third-person view, like NWN (I always play it with the camera zoomed very far out). The Community Patch is more or less mandatory.