Garfield minus Garfield
http://garfieldminusgarfield.net/

"Garfield Minus Garfield is a site dedicated to removing Garfield from the Garfield comic strips in order to reveal the existential angst of a certain young Mr. Jon Arbuckle. It is a journey deep into the mind of an isolated young everyman as he fights a losing battle against loneliness and depression in a quiet American suburb."

It's also quite hilarious...

Two of my favourite albums remain:

Famous Blue Raincoat - Jennifer Warnes covers Leonard Cohen
Nilsson Sings Newman - Harry Nilsson covers Randy Newman

Can anyone better those? (must be a single artist covering another single artist)