I know it's an old thread but...
Eddie Fisher and Carrie Fisher were father and daughter
as were
Tony Curtis and Jamie Lee Curtis
Jennifer Aniston's godfather was Telly Savalas
then there's the many Fondas
Elizabeth Shue (cocktail) is the sister of Andrew (Melrose Place)
The mob boss from Goodfellas is the RL dad of Romy in Romy and Michelle's high school reunion
Diana Ladd is Laura Dern's (Jurassic Park)mum
Nicolas Cage (who was married to one of the many Arquettes) is Francis Ford Coppola's nephew
Vanessa Redgrave is Joley Richardson (and the late Natasha's) mum, her brother was Andie McDowall's husband in 4 weddings. To further complicate things, Natasha was married into the Fox/Harris family comprising Laurence Fox (Mr Billie Piper), Emilia and one of the Dumbledores in HP.
Judy Garland was Liza Minelli's mum
Trigger from Only Fools and Horses is Emily (Wish you were here) Lloyd's dad
Isabella rossellini is Ingrid bergman's daughter
the singer Rosemary Clooney is George's aunt
Joey (Blossom) and Matthew Laurence (Boy meets world) are brothers
when I was young and watched Dallas I never realised that Precilla Presley was married to Elvis and was Lisa-Marie's mother
Jasper Carrot is Lucy Davis's dad