I'd go with the Hart Foundation. But no mentions of the Corporation, Million Dollar Corporation, Camp Cornette, The Union, The Un-Americans, or Evolution? Gasp.
Also I think the Dangerous Alliance/Team Angle stable that Heyman was building up before WM (Angle, Team Angle, Big Show, A-Train) could've been pretty cool if it had lasted longer. Playas, Inc. is also a badass stable.