Odhanan
Adventurer
Nope, D&D had it first with 1e bard.
Well, yes, you are right for the "egg or chicken trivia" aspect of the question, but let's face it : PrCs owe a lot to WRPG and its system of careers with a kind of "RoleMaster twist" to it.
Cthulhudrew: I basically agree with your criticism, but I think that the PrCs are best used when describing factions, organizations and other background elements of the campaign world. When they are used in conjunction with it, and not apart from it, only as rule mechanics, or 2nd edition kits, if you see what I mean.
What frustrates me often with PrCs are the prerequisites. Not that they are so bad, but the requirements often ask from a player to think on a metagame point of view, to specialize and sacrifice character development for the sake of the "right feats at the right time to get the PrC at this precise level". There are just too much mechanical requirements to PrCs, and not enough RP requirements (know members of the group, have a personality like this or like that) in my opinion.
Nothing that can't be modified at home, obviously, but still.