since we talking about old times i just wanna do some kind of honorable mention:

Game:

Eye of the Beholder, Eye of the Beholder II - The Legend of Darkmoon


Developer:

Westwood Studios


That being said, for me personally, the best RPG of all times isnt really crystal clear. Eye of the Beholder 2, Baldur's Gate 2 and Pathfinder Kingmaker are all three candidates. Maybe Baldur's Gate 3 will soon be up there aswell, it has potential for sure. I'm replaying Pillars of Eternity right now (Never really finished) and plan to play Pillars of Eternity 2 after finishing the first one, so, we'll see if they are as good.

Also, please don't forget, Owlcat is doing another cPRG which might be released at the end of next year (Wrath of the Righteous).