The Drzes HMS blows all other CP's out of the water. It doesn't need a clean system install, puts a lower load on the server than Cpanel and Plesk, has automated setups, has INTEGRATED billing (unlike Cpanel where you have to buy Modernbill), and even works for the average joe webmaster.
Nothing else holds a candle... check out the demo and see for yourself...
www.drzes.com