Mine have all come from sports team participation and spread from there:
Bones - from football, still sticks, I have always been really skinny
White Shadow (later deteriorated into "Whitey") - HS basketball team nickname
Dirt - from college basketball team, as in "older than", at 23, I was three to five years older than everyone else.
Also was called Hose by a big circle of non-athlete friends in college - from a loud, complimentary reference my drunken ex-girlfriend made at a party.
Of all these, I obviously wish that "Hose" had stayed.
A teammate of mine, incidentally, had what I thought to be the coolest nickname - "The Colonel". It was an A-Team reference, his last name was "Decker".