Hopkins, Mayorga, Tarver, and Campbell would top the list. On the real I'd have to say Mosley is one of the most humble boxers I've seen.
I will say thing again (and again as long as this silly thread proceeds) : It is a bull**** facade. No one becomes a legend in boxing (or anything else) by being truly humble. In their heads none of the great ones are humble for a second. - Jason