Dexter to Star Trek the Next Generation

Nina Batista on Dexter comments on her husband Angel's two Doublemeat burgers from Buffy's Doublemeat Palace.

Angel was a spin-off of Buffy the Vampire Slayer

John Larroquette Show referenced Yoyodyne. Yoyodyne was also a client of Angel's Wolfram & Hart.

THe John Larroquette Show reference Yoyodyne which is the company that makes some of the starships mentione on Star Trek: TNG