Quincy ME to Touched by an Angel

Both have characters that have flown on the fictional Trans Global Airlines

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

Promised Land's Russell Greene helped his boss Ryan Matthews face his families past, then Ryan crossed-over onto Diagnosis Murder to ID the body of one of his ex-wife's old friends

Promised Land was a spinoff of Touched By an Angel.