-Xzar and Montaron because they’re insane and homicidal and hilarious
-Quayle and Tiax for egoistic gnome shenanigans
-Alora to piss off Montaron
-Tiax and Xzar also get along swimmingly
-Overpowered Fighter/Mage protagonist cheeses through the entire game while the rest of the party banters about their bullshit
Baldur’s Gate 1 is a pretty simplified and easy game compared to 2, but it’s shit like this that sometimes makes it worthwhile.
The banter is really unvaried and low in quantity, though. I think mods and whatnot have obscured this fact over the years but while BG2 has tons of party interaction and deep dialogue trees, BG1 had very little meat to its NPCs. Each of them has some quest right when you meet them, but beyond that you might get like a single exchange of one-liners every few in-game days and that’s it. Also, those “quests” sometimes are barely anything, like how Kagain is like “Let’s look for my lost caravan!” then immediately says “Eh, forget it.” Either that or some of them are hidden in Baldur’s Gate and the incentive to mess with your party composition by that point is minuscule, especially since those characters are mostly actually worse or just redundant.
Infinite Engine games: Baldur’s Gate 1 nad 2, Fallout 1 and 2, Icewind Dale 1 and 2, Planescape Torment.
Games following in that line: Divinity Original Sin 1 and 2, Tyranny, Pillars of Eternity 1 and 2, Torment Tides of Nunemera, and Pathfinder Kingmaker.