The band, They Might Be Giants has a fun wiki called: This Might Be a Wiki

They have songs, lyrics and information about upcoming and past concerts. Users can add information about concerts they have been to and add themselves to the list of attendees at the concert. - Susan

I found a great pet Wiki here is the URL  Who let the dogs out??

http://lomac.vox.com/library/video/6a00c2251c078e549d00e398e9e1ab0004.html 

What's your favorite Wiki?