Bard.
Because they sucked in previous iterations of D&D, but with D&D5, they now feel like a full featured class. Except I'm annoyed I cant use inspirations on myself.
My first character in BG1 was a Bard, but I soon learned that they are basically just massively crippled Fighter/Mages with some random but really irrelevant features, such as very high Lore. Allowed to wear armor, but cant, because then you cant cast spells. But cant cast many spells anyway. The song is poor, hardly ever develops, and makes you stand around passively. Etc. Awful.
Now with BG3 Bard is uber fun. For the moment I picked Halfling, to be even better at skills.
Other than that:
Fighter - Its kind of okay, but really they are still sort of boring, lacking options.
Barbarian - The literal one trick pony, but not bad. Fast movement for example is fun.
Paladin - Definitely my favorite kind of warrior. Third favorite class overall.
Ranger - See Rogue. Stealth is too slow. Not much of a fan of Druid magic either.
Rogue - The D&D5 Rogue rocks, but I'm still not into them. Stealth is too slow.
Cleric - In MMORPGs the Cleric has been my main. In offline games I never make them the protagonist. Too passive.
Druid - Never really connected much to Druid. In D&D of course I always had one in group, as second healer next to a Cleric. Now in BG3 theres no space for two healers though.
Sorcerer - Was my favorite class in BG2. In BG3 they are still my second favorite, after Bard.
Warlock - Dont really care about those.
Monk - Dont really care about those.
Favored Soul, Shaman, Psion - I was honestly surprised none of these are present in BG3.