How bout a Monk/Sorc/RDD. Granted i've never tried this in pnp DND (only on NWN) so i don't know how well it would work but i think A Monk/RDD (with 1 level of Sorc for Preqs) complementes each other fairly well. By the time you get to level 15 for example (granted a pretty high level), you have a level 4 monk/1 sorc/10 RDD. While the Monks fists at this point aren't doing a huge amound of damage (unless there is some kind of modifier for the RDD's "Natural Weapons") you do get some great Stat Mods, flying, imunity to fire, mind effecting spells, etc etc. I don't buy into that whole powergaming thing so i'm not sure if this build is the "most powerful" but it seems like fun and has alot of fun and has some great role playing possibilities.