Now that I've finally got the less bugged (since she is still very much buggy) Minthara to wrok, she is my favourite non-origin companion, together with Jaheira. She is evil, but doesn't try to create any drama, and I've found her commentary (e.g. on Ketheric) quite insightful at times. Jaheira was one of my favs in BG1 and 2, and I think they have kept her in character, so that was no surprise that I liked her.

As for the origin companions, I have a soft spot for Wyll, because he was the only guy in the party that did not act in a way that I'd consider problematic (or even creepy) on my first playthrough. Which just reminded me how low the bar was. smirk
And I also like Karlach; her being cheerful and friendly was a nice counterpoint to the drama between Laezel and Shadowheart.

It might be because I simply like exploration and adventuring, and I'm not looking forward to playing conflict mediator or counselor, but after a few playthroughs, I just don't feel like recruiting some of the companions anymore.