I had a full group, mostly - my fighter from BG1 kitted to Kensai and dualled to mage (yeah, too easy, but it was my 1st runthru, and I didn't know); Imoen/Yoshi, Minsc, Jaheira, Nalia/Keldorn, Aerie.
Jaheira I had dropped early in BG1 because she was bossy and annoying, but I found her much more interesting in BG2 (In fact, I spent time redoing part of SoA once I found out about romance glitches). I released Nalia as soon as her quest was over (didn't like her attitude), and 5-grouped until I met Keldorn. I should have let Aerie go, too - but I pretty much kept the PCs as I met them, besides, I felt "obligated" to help her grow a bit, despite her whines
. Man, I hate it when react to a software-generated toon. My party wasn't a "power" party, but was based on the characters that I got along with as I met them; after all, I was following a story arc, not just playing a tactical AD&D simulator.