BDIONU (an ATC guy) always makes me laugh when I read it.
Takan Inchovit is pretty good, too.
Clare Prop is the best female user name, it's a great pun.
My other faves have already been mentioned.
P.S. Actually if you're familiar with Greek mythology Kharon is pretty good too, particularly given your usual posting subjects. (If you were fishing for compliments, you got one
).