Andy Barker, P.I. to Castle
5 connections
Andy Barker, P.I.
Buffy the Vampire Slayer
Guy Helverson from Andy Barker, P.I. owns a Doublemeat Enterprise from the Doublemeat Palace episode of Buffy
The X-Files
The X-Files? Cigarette Smoking Man and Buffy the Vampire Slayer's Spike both smoked Morley cigarettes.
Homicide: Life On The Street
Homicide's John Munch questioned The X-Files' The Lone Gunmen.
Law & Order
Law and Order and Homicide crossed over on four episodes
Castle
Hudson University from L&O also appears as the home of various victims and crimes in Castle,