I think we had this thread a long time ago, but hey, why not?
Mine:
Jamesman (yep)
Ishboo
Modercai the Dancing Yiddish Clown or, alternatively, Mordecai the Dancing, Juggling, pink-hat wearing, formerly sleeping yiddish clown
Bobo
Billiam (like William)
Jamesberry
Jimbob
Big Bird