Top 100 April Fool's Day Hoaxes Of All Time
(as judged by notoriety, absurdity, and number of people duped)
A pretty funny and long listing of April Fool's Day Hoaxes. I have to say that the Europeans as a whole (especially the British and the Russians, both whom I would not have expected it from) have a pretty damn funny sense of humor.
What's amazing that none of the recent internet shenanigans are listed there, most of which I find really funny.