I have personalized ringers for my addy book...but for general calls...I'm currently using that Hershey's Christmas Ringer. It's super loud & fun for the moment.
99% of the time, my ringtone is "VZZZZZZZZZZZZZZ VZZZZZZZZZZZZZ". The other 1%, when it's not on vibrate, my current ringer is by Gang Starr, 'Step in the Arena'. I don't do all that contact-specific ringtone stuff.
Default - Cummins diesel starting up
Wife - AC/DC - Got you by the balls
Buddy from work - Duran Duran - Hungry Like the Wolf
Mom - Elvis Presley - The Wonder of You
I also have Michael Jackson - Bad, Metallica - Cyanide, and TI - Whatever You Like on standby to be assigned.
I love that I can just cut up an MP3 to make my own tones.