[Ereet]

Most classes I feel like one player is as good as the next, but for the ones that aren't:

Necro: Athiyk
Enchanter: Glitch (Butch was also awesome, but he quit super early on)
Monk: Krimz or Emil
Bard: Jete

Shaman is another class I think takes some skill, but it is really hard to say since they didn't really break out until Kunark and more so in Velious. Of the people I played with a lot, I always thought Bossco did a really good job.

The rest of the classes I feel like all you really need is common sense so it is hard to say.