Eureka to The Wire
4 connections
Eureka
Warehouse 13
Fargo from Eureka visits Warehouse 13 in a crossover episode
The X-Files
On Warehouse 13 Mrs. Frederic and Steve Jinks enter The Library, a secret room in the Vatican. There is a pack of Morley cigarettes on the table
Homicide: Life On The Street
Homicide's John Munch questioned The X-Files' The Lone Gunmen.
The Wire
On The Wire (episode "That's Got His Own") Junior Bunk from Homicide was mentioned as someone who had once put bad drug product on the market causing deaths.