I recall this being at the top of /r/webdev 3 or 4 years ago. It turns out that a lot of the subsections have their own themed 404s as well.<p>My personal favorite: <a href="https://www.bloomberg.com/politics/404" rel="nofollow">https://www.bloomberg.com/politics/404</a>
In a similar spirit, the Bloomberg Businessweek magazine used to have zany cover designs (my favorite featured a sweaty Steve Ballmer in a Clippers jersey dribbling a basketball captioned "<i>BASKET BALLMER</i>") but they've since switched to plain, solid colors.