What's the best way to bring back a corrupted file from my digital camera?

Swing the carcass of a dead black cat counter-clockwise over your head while chanting "I wish I still shot film."

if you really want it, then DO NOT delete it. Save the file or pic somewhere. A time may come when there is a program that can read the corrupted file.
if u cant wait, try opening the pic with different photo programs. Some programs might be able to view the corrupted file .