I thought "Facebook" on betfair was disturbingly hilarious.
NOLUBE also seems like a player to be feared.
I remember in the last thread there was one about a guy named OMGPOKAR!! and every time he got sucked out on he'd type his own name so it'd look like:
OMGPOKAR!!: OMGPOKAR!!
I got a laugh out of that.
Also shameless self promotion my name is Stylin_On_U and you'd only find it funny if you watched this:
http://www.youtube.com/watch?v=ff_gAV--x3M