Several other folks have mentioned the Colt 6920/M4's that are sold by Wal-Mart. They include (at least in my local stores), the basic 6920, the Magpul edition, and the railed-out SOCOM style.
I've got my eye on the version with Magpul furniture, admittedly because I thought it looked sharp and it's not quite as spendy as the SOCOM one.
Does anyone know if the BUIS on this version are also Magpul manufacture? In the glass case they kind of all look similar.

