My wife was flicking around the TV channels the other day when she came upon a 1992 rerun of "Mad About You." In it, Paul and Jamie Buchmann (Paul Reiser and Helen Hunt) are married and living together, but he still has the apartment he'd lived in as a bachelor, which he's been subletting. She convinces him that it's finally time to give it up, so he goes back to talk to the tenant, who happens to be a character on the show that preceded "Mad About You" on NBC's Thursday primetime schedule...
That wasn't the only crossover between "Mad About You" and another NBC hit. Lisa Kudrow, who played Phoebe Buffay on "Friends," also played her twin sister Ursula on "Mad About You," and those two worlds collided in a crossover, too...