If you had wondered that Wikipeda is the only site which provides most information think again. Its internet and there are people running projects and wikis which provides good information on specific topics. Here is the compiled list of sites which are like wikipedia.
#1 LostPedia : Dedicated to ABC’s hit TV show Lost
#2 CigarettesPedia : CigarettesPedia is unique, the fullest free collection of cigarette boxes, invaluable information about cigarette brands, history of their appearance and the manufacturers.
#3 ConservaPedia : Conservapedia is a clean and concise resource for those seeking the truth
#5 Downloadpedia : Its is an extended library of freeware, shareware and commercial software for Windows, Linux, and Mac. Downloadpedia.com is intended for those who are looking for tools.
#6 Free Thought Pedia : The idea here is to provide a place to link to which saves time in having to repeat many common arguments or dispel false assumptions (for example, Is Atheism a “belief”?)
#7 Uncyclopedia : Uncyclopedia is the official encyclopedia of Unicycles. It has all the information on unicycles that you will (n)ever need. (But if you ever need any more, you can just add it because it’s a wiki.) Uncyclopedia is a place for unicycle enthusiasts to share all their greatest unicycle secrets! Go 1 Wheelers!!!
#8 Battle Star Wiki: The Battlestar Galactica Wiki (a.k.a. Battlestar Wiki) is a free online encyclopedia and episode guide covering the Science Fiction series, the original Battlestar Galactica, Galactica 1980, and the re-imagined Battlestar Galactica.
#9 WikiHow: wikiHow is a collaborative writing project to build the world’s largest, highest quality how-to manual. With your edits, we can create a free resource that helps millions of people by offering solutions to the problems of everyday life.
#10 WikiTravel : Wikitravel is a project to create a free, complete, up-to-date, and reliable worldwide travel guide. So far we have 19,032 destination guides are availble.