I personally found Finch insufferable: annoying soundset and predictable, hyper-nerdy attitude. Plus she is a divine caster, and there are already enough of those in BG1, all of which are a lot more enjoyable to lisen to.
I also tried out Gavin for BG1, whom I ditched even more quickly than Finch. Preachy, holier-than-thou attitude and seemed like an uninteresting character in general.
For BG1, I liked the Mur'Neth (or however you spell his name) mod, but unfortunately he is not the most useful character around, as his class is pseudo-Thief with some unique abilities, and you can get much more versatile thieves from the vanilla cast. Still, the concept of his character is interesting, and his soundset is also well done and humorous.
I also tried out several NPC mods for BG2, out which I liked Ghareth who is a low-level Fighter/Mage with a straightforward and honest personality, and Keto who is probably my favourite NPC mod when it comes to writing, but unfortunately an unkitted bard is totally useless in BG2. Still, she adds a bit of quirkiness to the existing cast. Played a bit with Kelsey in my party too, but found his "guy next door" personality rather generic and boring, but from a gameplay perspective he can be interesting, since he is a Sorcerer.
Xan for BG2 I found so-so, his dialogues, while generally well-written, get old very fast since there are just way too many of them and - as you would expect from him - are rather whiny. Coran for BG2 way okayish, and the Branwen one was quite dull.
tl;dr, out of the ones I've tried I'd recommend Mur'Neth for BG1, and Ghareth, Keto and Xan (if you don't mind his constant moaning in his conversations with the PC) for BG2.
Post edited December 04, 2013 by szablev