The name of the guardian angel in It's a Wonderful Life is rarely heard the rest of the year because of its studious, near-nerdy image, but this could change in the current naming climate.
An English peerage title, Clarence enjoyed great popularity at the turn of the last century, reaching as high as Number 18 in 1900, and staying on the list until 2010. It has two prominent legal bearers--Clarence Darrow, defense attorney at the Scopes Trial, and current Supreme Court Justice Clarence Thomas. We can thank Clarence Birdseye for the invention of frozen food. Aretha Franklin and Louis Armstrong both named their sons Clarence.