I recently went on a binge and played several games through and have gotten a pretty feel for most of the NPCs. Was wondering what everyone thought about them.
It's hard to say that a certain NPC is "better" than another, because ow good they are really depends on the setup of the party, but I'll give it a shot in a general sense anyway.
Also, I've only run all the way through with good parties. I've run some evil parties, but never finished a game with one, so I'll focus on good guys:
1) Minsc - Super versatile. Can either have with dual wield maces or go with Spiderbane and Composite Longbow. In many runs I've given him the Tomes of Constitution, Dex and Strength, depending on what my PC is and if I have him using the Gauntlets of Dex or not.
2) Kivan - Also super versatile. I use him as an archer with dual wielding longswords when against opponents that are resistant to missiles. He almost always has the most kills in the party.
3) Imoen - I find her to be super useful. I always dual her at Thief level 5. Dualed at 5 she has 60 pick locks and 95 find traps. 60 pick locks is really all you need because potions / knock. When dualing at 5 you can quickly get her thieving powers back and he still gets to level Mage level 9.
4) Yeslick - I used to not care for him too much, but once put both the Gauntlets of Dex and the Big Fisted Belt on him I loved him. Works great either with ++ in Single Weapon Style or Two Weapon Style.
5) Coran - Hard to argue against Coran, but if I have Imoen in the party I often don't take him. If I do plan on taking him I bring some potions of perception with me so he can get through Cloakwood is the only trap finder.
6) Xan - Technically, Dynaheir is probably a better Mage only because Web is so OP, but Xan is more fun IMO, cause Webbing everything, while powerful, get's old. Also, if you're webbing then that hampers the use of Haste, so... So, IMO, Xan is better than Edwin because while Edwin get's more spells and has better health, the -2 to saves on Enchantments is uniquely powerful.
7) Dynaheir - She's really good, and her -2 save Web is basically the most powerful spell in the game. Her lore is also practically Bard level, which is a nice bonus.
8) Jaheria - I used to think she was horrible, but once I figured out to co equip her to be a good tank I came to like her. Still, she's an inferior version of Yeslick.
9) Adjantis - I used to think he was the best tank, but meh. Now I think he's not so good. He's perfectly fine, but also totally average. Doesn't really stand out in any way.
10) Branwen - I just don't see the use in a pure cleric for BG1.
11) Khalid - No, just no. The best thing to do with him is turn him into an archer, but why?
12) Garrick - If I want a Bard I'd rather roll my own kit. I don't care for base Bards. Just not worth the space in the party to have him in it IMO.
No meaningful experience with the rest.
BTW, most of my parties are 3 - 4 in size.