A manga (well, mahwa) reccomendation:
iD_Entity (aka
Yureka). It uses the D&D rules by-the-book, but adds in a number of classes which would be quite interesting to play (witches, for instance, can enchant
brooms of flying for free, and at high levels can cast any Wiz/Sor spell by increasing its casting time by a factor of ten). Oh, and it's very funny.
There is one character who has dipped in dozens of classes and taken obscure feats in order to duplicate a ninja (much to the game-makers' annoyance - "There are no ninjas in Lost Saga."
). The guy is at least level 40, even with multiclassing penalties in effect, but does not have access to any of the powerful class-based items the other characters use.