Since Samuel Beckett's "Waiting For Godot," the characters we don't see have been far more powerful than the ones we do. We've never seen Waiting For Godot and never go to the theater, so we looked at Wilson, Nanny, and 10 other TV personalities everyone knows, but nobody recognizes.
http://www.collegehumor.com/article:1787179
From the Upcoming ueue, submitted by CheeseDuck.
What about "Big Face Girl" from Wings?
Really, the article should've been titled "Characters *Whose Faces* We Never See."