I know 6A 119 and 4A 152 has some big names, but for depth and loaded with quality wrestlers I think 5A 135 is toughest:
Tyler Koehn Pitt-37-1
Mark Millstead STA-35-3
Alden Isenberg GE-26-4 3rd 2005
Kyle Buehler LAN-37-1 4th 2005
Austin Jonas KMC-37-4 4th 2005
Thomas Pipes WIN-33-10 4th 2005
Tom McDonald BC-25-6 2nd 2005
Jeremy Plott SS-23-12