Hank Williams/Hank Williams Jr./Hank Williams III all became famous in their own right.
Conrad Hilton/his sons Barron & Nicky Hilton/the current Hiltons are all better known than most hotel families would be (i.e. none of the Marriotts or Statlers are famous or infamous)
I would totally watch Joss Whedon’s Sesame Street.
The Barrymore familygoes back at least a century and a half, especially if you’re counting the Drew branch, which is a notable acting family in its own right. Acting families like that are fairly common; consider the Kembles, a famous British acting family, and the Booths, a rather infamous American one.
In the history of astronomy there are the four generations of the Cassini family who were successively the first four directors of the Paris Observatory. To avoid confusion, the convention has had to be established of referring to them as Cassini I, II, III and IV.
But this, like several examples in the thread, is really just an example of a “family firm”. Only Cassini I was truly exceptional and independently famous, with the others then good enough to inherit the position from their father.
Clifford Arquette (Charlie Weaver), his son Lewis Arquette, and all the Arquette grandchildren: Patricia, Rosanna, Alexis (formerly Robert), Richmond and David.
In my own neck of the woods, Dwight Morrow was a famous stateman and ambassador to Mexico, his daughter Anne married Charles Lindberg and wrote really good books, and their daughter Anne Lindberg writes children’s books.