If you haven't seen it yet, AMC's Breaking Bad is one hell of a crime drama show.

Homicide: Life on the Streets was an NBC show based on the book Homicide: A Year on the Killing Streets written by Wire co-creator David Simon. The Wire also borrowed heavily from the book, in fact the entire first scene of the series, with McNulty talking to the man about Snot Boogie was taken from an actual event chronicled in the book. Even a few of the actors show up in the earlier show, JD Williams, the actor who played Bodie shows up in an episode of Homicide. However what connects the two shows is the sharing of the character Detective John Munch who appears in an episode of The Wire as a bar patron arguing about how a customer's tab should be handled. In the show Homicide he and a few other detectives own a bar and have a detective's wake very similar to the three seen in The Wire. Ergo the popular theory is that the world's are linked, along with the Law & Order world as well as The X-Files'.