While browsing online I found three wikis that I thought were quite interesting. here are the URLs:

http://watchmen.wikia.com/wiki/Watchmen_Wiki
 This was pretty straight forward, just a wiki of pretty much everything Watchmen related. Everything from character backstory to plot analysis to the symbolism laced throughout the comic.

http://wiki.verbix.com/
 A wiki to help with learning many different verb conjugations in different languages. Of course, these are all VERY simple versions of it and have just the bare minimum. However, it makes up for it by having over 500 languages.

http://guitar.wikia.com/wiki/Guitar_Wiki
This was just a very basic wikia on guitar related news. From music to new release of guitars and guitar related merchandise.