The best 404 error message ever...

Ok, not really, but the image used at Offbeat bride really made me smile:

So friggin' adorable!

Some other great ones:

"Our princess is in another castle."

A personal favorite, Homestar Runner's Teen Girl Squad gets 404'd!

The classiest dang 404 I've ever seen. Beautiful composition!

Love the scrolling star background on this one!

Nerdy guys in sweater vests, and instructions not to cry? Hilarious!