BG2 Companions (but not quite because slightly less interaction): Aerie, Anomen, Cernd, Edwin, Imoen, Jaheira, Jan, Keldorn, Korgan, Mazzy, Nalia, Viconia. (Characters who EITHER have a quest after you get them or you can romance.)
BG2 sidekicks: Haer'Dalis, Minsc, Yoshimo
Some people like Minsc despite him not having 'companion level' interaction. Some people never romanced Aerie, Jaheira, Anomen or Viconia, and thus didn't get the extra interactions with them, and still didn't mind having them around. Not many people criticised BG2 as being 'Frankensteinish' or whatever for having NPCs with varying levels of interaction.