It may be the best 404 but the 503 isn't so nice :). I'll check back later.

A poster child for irony. The 404 is so popular, you get a 503.

I've always been partial to http://www.plinko.net/board

"Quoth the server, 404".

Not sure if it's where they got it from, but I have seen it as part of a larger poem on bash.org.

I like this one by Nosh: http://www.nosh.com/404

Because it's not enough that you can't give the user the page they asked for, you have to disturb the quiet in the office without warning as well.

(Please, add to the title that there's sound.)

"disturb the quiet in the office"

Oh you mean you were secretly browsing at the office? ;-) You know, in almost all cases the 404 page fits the website you're browsing.

Sorry about that. I had my sound off when I saw it.

Dropbox is still my favourite: http://dropbox.com/404.html

THCNET's is still my favorite:

http://thcnet.net/error/index.php

i like this one http://www.mindomo.com/404