Joey to NCIS: LA
10 connections
Joey
Friends
Friends'Joey spun off onto his own show Joey.
Caroline In The City
Caroline in the City's Caroline wished The Single Guy's Jonathan good luck
Frasier
Fraiser's Niles and Daphne read Caroline in the City's comic strip.
Cheers
Cheers spun-off Frasier
St. Elsewhere
St Elsewhere's Westphall, Craig and Auschlander visited Cheers' bar
Homicide: Life On The Street
St Elsewhere's Dr Turner was investigated for murder by Homicide's Pembleton and Bayliss.
Law & Order
Law and Order and Homicide crossed over on four episodes
Arrow
Hudson University is the fictional University where many Law & Order characters graduated as well as the location of F.I.R.E.S.T.O.R.M. On Arrow
Hawaii Five-O (2010)
Hawaii Five-O references Dominic Alonzo from Arrow
NCIS: LA
NCIS: LA and Hawaii Five-O worked together in a crossover episode to stop a smallpox outbreak