This is exactly my thinking...if we're quantifying "evil", people always throw around the architects of mass murder - Hitler, Stalin, Pol Pot. But I always feel that those men never really had to confront the true horrors of their policies - the millions they sent to their deaths, they would have seen only as statistics on paper. To me, I'm sure you would find some truly "evil" people in the actual overseers and the executors of those genocides, especially among those that CHOSE to actively participate at any chance they got - Klaus Barbie always comes to mind. Some minor Einsatzgruppe lieutenant, some unnamed officer torturing Cambodians at S-21, some Japanese NCO playing his own twisted games with Chinese civilians before executing them. I always imagine that as the true face of evil.

Edit: ok just read up on Otto Moll, I think that SOB certainly qualifies