Windham or the Mossberg MMR is the best bang for the buck pre-built AR15 that doesn't come accessorized out from the get go.
http://www.youtube.com/watch?v=0PVEitTfxm0
MAC review for Windham
A friend picked up the Mossberg MMR hunter. It was in one of the camo patterns. Nice gun and had zero issue out of the box. Was shooting MOA at 100 yards but not sure what ammo he was using or anything. I was impressed with it. Especially for the price (think he paid like 700 for it)
Windham is a company i am hoping really gets their feet of the ground. Being fired from Bushmaster and then forming your own company and starting from the ground up is rough.