Dexter to Person of Interest
4 connections
Dexter
Buffy the Vampire Slayer
Nina Batista on Dexter comments on her husband Angel's two Doublemeat burgers from Buffy's Doublemeat Palace.
The X-Files
The X-Files? Cigarette Smoking Man and Buffy the Vampire Slayer's Spike both smoked Morley cigarettes.
Fringe
Fringe makes reference to The X-Files classification of files.
Person of Interest
In the pilot of Person of Interest John Reese's suspect Diane Hanson has emails numerous characters from Fringe