I is for...

"Incontheevable!"

One of the most classic lines in teh history of film-making (I know, blasphemy, but it's true). Wallace Shawn, who plays the overly-intelligent wannabe criminal mastermind, was almost one of those actors who's in a bunch of stuff that you know but can't quite name, but his role in The Princess Bride saved him from such a fate! (Other actors who've dug themselves out of a similar woodwork: John C. Reilly, Thomas Haden Church).

And so, some internet nuggets of Inconceivable things, that, well, good grief, do exist.