For pure insanity, gotta love Xzar, Tiax, and Bassilus. For weirdness, there's the Drunk by the Beregost temple, and Maple Willow Aspen and Borinole Mann in BG. Also, I once role-played a Druid through ToSC, and got into an interesting conversation with a girl named Farthing: She's not old enough to hunt yet, and wanted to know if I was allowed to hunt. I, being a Druid, said that animals should be cherished & respected, not hunted & killed. She thought that was silly--if we didn't eat animals, what would we eat? I then told her of the mystical bush that gives the fruit called Tofufruit, as well as the Sacred Couscous and the Holy Bean Sprouts. "These and other bland, unappealing foods await those who renounce the consumption of flesh." I was busting up! GOTTA love it.
Also, is it me, or did the Mages ALL get great voices? I happen to love Xan's pessimistic tone, Quayle's whiny bragging, and Edwin's hideously inflated ego. Whenever I do an Elven Mage/Thief (which is a lot), I always give him Quayle's voice, and I usually hack his CHA down below 8 to complement it. In the party I've got now, I'm using Quayle's voice, Dynaheir for my Cleric/Mage, and Xan for my Ranger. ("We should all save our effort and just lie down and DIE.")