In high score tables, you usually have 3 characters to make your mark. HEX is a pretty easy one for me, what about you fine folks?
Heh, I'm reminded of that Fate/Stay Night fighting game that wouldn't allow me to put in "ASS" on the high score table.
It was also funny because the default table had all the different characters in it with the first 3 letters of their name as their signature. All the characters except for "Assassin" that is.
If its one of those arcade machines, I usually screw up and put some random letters, if I don't mess up (which I usually do) I go with MUN, because Man. United. I think two years ago my friend and I got the high score on one of the games in chuck-e-cheeses and we put something stupid like FUK or something stupid like that.
Depends on what kind of game I'm placing for. In a public arcade I'll generally go by "CFC," just in-case the impossible happens and people recognize my talents. Other than that, I use KND, whish is the 3 character abbreviation for "Kind," since I use that word a lot in my user-names across the board.