Okay, these are my family's nicknames. I apologize in advance if these are lame (it IS my family, after all):
Messi - El Tortuguin (Spanish for "little turtle" due to his striking resemblance to the hard-shelled reptile).
Ronaldinho (back in the day): Caballo (Spanish for "horse" because...well, just look at his front teeth).
Pinto - Trujillo (because he resembles Metallica's bassist).
Xavi - Cejon (Spanish for a guy with never-ending eyebrows).
Milito - Chilito, just because it rhymes.
Pique - Picaron (the Peruvian version of a donut).
Marquez - Mariquita (this is REALLY bad!)
I'm sure there are more, but I can't think of them right now. :smile: