With the introduction of new do-everything cellphones, and hacks for said phones that allow your own ringtones, it's time for us to start making our own. I'll start with some straight loops.

A robotic, futuristic, George Jetson ringtone:
Craig Mack - "Flava In Ya Ear (Ringtone)" iPhone

Geechie Suede got cha wiiiide:
Camp Lo - "Luchini (Ringtone)" iPhone

100x times better than "Axel F":
Van Halen - "Jump (Ringtone)" iPhone

(My personal fav) For all the doo-doo chump punks:
Digital Underground - "Humpty Dance (Ringtone)" iPhone