I'm going to second Wildshape Mystic Ranger/MoMF. Honestly, Rhino's Rush or Hunter's Mercy spam should keep your damage reasonable. I personally like Warforged, despite the Wis penatly as you get to keep armor while Wildshaping, and get a Con boost.
Of course, a T1 caster always works, even if it is the boring answer. If you want to go that way, I recommend an Arctic Grey Elf. +2 Int +2 Dex -2 Cha -2 Str. Pretty good deal.
If you're feeling really spiteful, you could build an Ubermount and laugh as you murder everything in your path. I, personally, really like the Ubermoose, but it's sub-optimal compared to the Ashworm or a Griffon, or even a Fleshraker(Not that that's saying much, the fleshraker is, well...), unless you're allowed to build the mount's feats and such from scratch.
Basically, everything in this thread will work fine. Well, except that Paladin/Monk joke.