Bought:

A vowel.

Sold:

My soul.

OH, wait... you meant musical gear. In that case, I have been a bad boy:

Bought:

MIM 60s Tele (used)
Schecter PT Custom (factory 2nd)
Crate V1512 (demo)
Dr. Z Maz 38 2x10 (used)
SF Vibrolux Reverb (used, obviously)
Epiphone Emperor Regent (used)
Taylor 414 (used)

Sold:

G&L L-1505 bass
Gibson L-4CES

Bought and sold:
Laney VC-30

But viewing some of the other lists, I don't feel quite so guilty. :-| CS