I chose Baldur's Gate but I haven't played all of the games mentioned because I stopped gaming years ago. PS:T, BG1 & 2 are great games but I'm also biased by nostalgia.
No WoW? No Fallout? list fail...that said Loved Neverwinter. Only jesting bout the fail but come on....no WoW?
MMOs nowadays are not what they used to be. I used to play WoW until WotLK then I kinda got tired of it...
Fallout 76 is crap. But Fallout 4 was okay, New Vegas was great, Fallout 3 was okay too. But my favorite was Fallout Tactics!
Only one vote for the witcher... And it was me. I'm disappointed in you all aha. The witcher 3 was something I'll never forget. Every side quest has more substance to it than most main quests in other rpgs like skyrim and fallout 4. It has the gritt of game of thrones the castles are so much more more immerisve when I went back to skyrim I couldn't help but laugh at "solitude" and "whiterun". Realistic swords too. I always hated the weapons in other fantasy games. Even skyrim vanilla swords were disgusting. If you haven't played it yet you should. After the first 5 hours you'll be hooked for the next 100.
I've never played The Witcher 3 but I'll take your word for it. TBH, I actually spent most of my hours playing the side quests of Fallout and TES because they were, for me, more interesting than the actual story.