I only want good-oriented and honorable companions, and I need at least five of them because I will only be playing the game with a mod that increases party size to six. Someone already mentioned Eder. Yes I love Eder. In both PoE games Eder is my always-in-the-party companion. In PoE1 I also similarly loved Sagani and she was always in my party too.
I don't care at all about my companions being "nuanced" or "flawed" because that's what's "realistic." If I wanted any of that, I can get that from real life. I play my cRPGs to get away from real life.
I loved Eder as a companion in PoE 1&2. Without any doubt, he was my favorite companion. I enjoyed the character development, the conversations we had, and the interactions he had with other party members. It didn't feel unnatural or forced. It felt real.
Well, the fact he was voiced by Matt Mercer surely helped.
This whole Eder love-in has been very interesting considering I'd always considered him to be the most 'conventional' companion you get in that game, more interesting because he's a sounding board for your character than anything in his persona history.