there was a cross-over episode between this show and Cheers once.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2573715897&category=18840

here's a description of the episode from TVTOME --

68. Cheers
gs: Rhea Perlman (Carla) George Wendt (Norm) Dean Jagger (Dr. David Domedion) Richard Lawson () Jessie Lawrence Ferguson () Lou Jacobi (Rabbi Singer) Jaclyn Bernstein (Betty) Eve Roberts (Margaret Domedion) Laura Esterman (Psychiatrist) John Mahon (Police Officer) Aaron Lohr (Boy) David Glasser (Boy) Amy Green (Girl) Jane Wyatt (Katharine Auschlander) Ian Freid (Jeff Rosenthal) John Ratzenberger (Cliff)

Mrs. Auschlander faces major heart surgery; Dr. Craig is disturbed to see the ravages of time on his mentor, Dr. David Domedion; Ehrlich searches for a religion; the messiah shows up for a Celtics game; and Dr. Westphall announces his resignation at a friendly little bar called Cheers.


b: 27-Mar-1985 w: John Masius & Tom Fontana & John Tinker d: Bruce Paltrow