Degrassi: The Next Generation to Gideon's Crossing

Degrassi: TNG was a continuation of Degrassi High years later

Degrassi High was a continuation of Degrassi Junior High

St Elsewhere's Dr Wesphall is paged twice on Degrassi Junior High. In the episode "Nothing to Fear" LD's father is in the hospital and Dr. Westphall is paged on the hospital intercom. Later, in the episode "Sealed with a Kiss", "Dr Donald Westphall" is paged, loud and clear, over the hospital intercom when Heather & Erica go in for a mono test.

St Elsewhere's Westphall, Craig and Auschlander visited Cheers' bar

Ivan Tiggs and Shirley Schmidt from Boston Legal go out to dinner at Melville's restaurant from Cheers

Boston Public's Principal Steven Harper appeared on an episode of Boston Legal

The Practice's Ellenor Frutt and Boston Public's

The Practice's Ellenor Frutt visited Gideon's Crossing's Dr Gideon about pregnancy complications