I would say that my major contributions have been the complete revamp of the article for the brilliant comic book Hitman, and have worked extensively on various pages related to The Wire. I can't take all the credit there -- several other users before me compiled massive amounts of data and story summary on all the character pages and episode pages; I have merely attempted to consolidate and simplify the information, wherever possible, while still maintaining some semblance of the intricacies that make it the best show in the history of television.
I also had a big hand in bibliographies for Joe R. Lansdale, Garth Ennis, Alan Moore, and Frank Miller. I have also tried to keep an eye on the films of the Coen brothers (especially The Big Lebowski, a page which has the tendency to get out of control without the help of several editors), and Matt Wagner's Grendel. My tendency, though, is to make lots of little edits to assorted pages, just to clean things up a bit.