On my X5M, "Jupiter" The Gas Giant. No explanation needed if you drive an X5M and have even bothered to keep track of your gas consumption. I haven't bothered with the "Gas" part of that name, but am trading it in on an X3 M40i for reasons addressing the "Giant" issue.
On my R8, "RDORGN" The New Mexico "Chili Plates" begged for this question, asked by all servers when ordering New Mexican food, "Red or Green?"