Hm.Plenty of the things I'm interested in TV/movie wise are connected.
Here's a (far from complete) list:
Doctor Who --> Moonlight--> Pirates
Sophia Myles was Madame de Pompadour and Beth Turner
Beth Turner happens to be in love with someone who is immortal.
Doctor Who --> Pirates
Jonathan Price was Governor Swann and played the Master in a Doctor Who Parody called The Curse of the Fatal Death
Captain Jack Sparrow and Captain Jack Harkness
Doctor Who --> Harry Potter:
David Tennant is the 10th Doctor/Bartimus Crouch Jr.
Roger Lloyd Pack was Bartimus Crouch and in two Doctor Who episodes was John Lumic.
Shirley Henderson who played Moaning Myrtle is in Love and Monsters
Camille Coduri is Jackie Tyler and was in Nuns on the Run with Robbie Coltrane (Hagrid)
Harry Potter-->Sweeney-->Pirates
Robbie Coltrane (Hagrid) was in From Hell with Johnny Depp
Alan Rickman was Snape/Judge Turpin
Timothy Spall was Peter/Beedle Bamford
Helena Bonham Carter was Bellatrix/Mrs.Lovett
Johnny Depp was Sweeney/Captain Jack