It's Always Sunny in Philadelphia to NCIS

David Brent on The Office (UK) wore a Sergio Georgini leather jacket. A Sergio Georgini bag was on It's Always Sunny in Philadelphia.

Charlie of Lost once dated a girl whose father worked for a paper factory in Slough. The paper factory in Slough is the paper factory of The Office (UK).

You can see advertisments for Oceanic Airlines in a LAX terminal, which is the airline of the plane that crashed on Lost

JAG and LAX reference the fictional airline Oceanic

NCIS was a spinoff of JAG