Better Call Saul to Melrose Place (2009)

Breaking Bad spun off the prequel Better Call Saul

Breaking Bad characters rented cars from the Lariat Rent-A-Car which Mulder and Scully frequently rented from on X-Files.

Brenda Walsh picks up a Morley smoking habit while in Paris on Beverly Hills 90210

90210 was a continuation of Beverly Hills 90210 years later

Melrose Place (2009) was a continuation of Melrose Place which was a spin off of Beverly Hills 90210 that was continued as 90210