As an unarmed martial arts enthusiast, I use to have this gripe with monks in the older games of this nature. The animations have improved somewhat since then, but seeing as a monk is meant to the master of unarmed combat, I was very dissatisfied that the animations looked like some drunk guy in a bar fight. They have improved a fair bit since then but could do with some work.
I also feel the melee, particular the fighter classes, although theyve improved from the rusty robot animations of the original baldurs gate era games, could do with another revamp.
One of the main reason in most of the games my first class choice has tended to be a more visually appealing wizard over the sword and board classes.
I'd be happy with more finesse and variety of movement in fighters and similar classes.