Fringe to One Life to Live

In the pilot of Person of Interest John Reese's suspect Diane Hanson has emails numerous characters from Fringe

In the pilot of POI numbers 4-8-15-16-23-42 appear as the time stamp of a surveillance camera, the same numbers won Hurley the lottery on Lost

The airplane that crashed and strand the cast of Lost was Oceanic Airlines Flight 815 also featured on Diagnosis Murder.

Diagnosis Murder's Dr Mark Sloan was defended by Matlock when Sloan was accused of murder

All My Children and Loving feature the fictional Trans Global Airlines

All My Children and One Life to Live crossed over a number of times