We recently made many additions to our site HollywoodNepotism.net!
Here's an abbreviated list:
Corbin Bernsen's brother (Roger Dorn in Major League) Collin Bernsen
Gary Busey's son Jake Busey
Bill Clinton's half-brother Roger Clinton
Matt Dillon's brother Kevin Dillon
Jack Nicholson's daughter Lorraine Nicholson
See these and more at HollywoodNepotism.net, and if you see anything we missed, let us know at firstname.lastname@example.org.