I always find it really fun to stumble upon a tampered wikipedia page, especially when they're random such as the Timon & Pumba article (for the actor Dominic West, see; Dominic West) or the Death from Laughter page (It is probably the most ironic way to die).
I also discovered that Dick Van Dyke's page is locked due to frequent vandalism, as is Michael Jackson's due to 'an ongoing high risk of vandalism' but is also a featured article, as is Kirsten Dunst's page.
Go to the wikipedia page on most vandalized wikipedia pages to find out more.
Some of them are:
beaver, Asinus, Keira Knightley, Jack Black, Giza, Zimbabwe, and Playstation 3.