I would like to meet more drow and demons (not tieflings - demons), and an interesting Dread Necromancer and undead even if he is an NPC. Also interesting is the Aasimar race as positive characters
Minthara is the best character and she NEEDS to be recruitable if you side with the grove!
Some well known characters of the forgotten realms such as Liriel Baenre ,Jarlaxle, Elminster (maybe disguised as a basic npc), one or more of the seven sisters etc...
A gold dragon or a silver dragon companion that helps the group disguised has a normal humanoid companion ( whatever the class), with multpiple occasions to unmask its true nature via dice/dialogue chacks.
It seems obvious but dragons are an absolute must be. Red dragon would be awesome. I loved Fiirkrag for everything he represented. He was a walking vanity, his wings attack would be epic if only animations weren't so inexistent back then. I would love to see a red dragon just "flush away" my team while slowly walking in the opposite direction.
I always wanted to learn more about Mind Flayers but we kinda have too many of them now lol.
And demons. I loved their riddles.
Alt+ left click in the inventory on an item while the camp stash is opened transfers the item there. Make it a reality.
Orcs and half-orcs! A kenku would also be pretty neat. Also I wanna fight a gelatinous cube, mostly because I have a hard time imagining how a fight like that would work in the game lol.