James Gasik
We don't talk about Pun-Pun
Ideally, if there's something special about character classes as opposed to NPC "classes", I'd think that the PC version of something a random NPC has (that isn't granted by something a player wouldn't have access to, like species) would be superior anyways.It's impossible to provide an adequate simulation of everything that is theoretically possible because that's infinite. If there's specific things a player wants then it can be homebrewed and would need to be fun and balanced against other features. Creating a trap options for PCs just because an NPC has something is the worst of both worlds.
Of course, that's assuming you think that character classes are a big deal in your game.