National Lampoon's Christmas Vacation is a film that stars an actor known for playing Dr. Leonard Hofstadter in what CBS sitcom?
National Lampoon's Christmas Vacation: National Lampoon's Christmas Vacation is a 1989 American Christmas comedy film directed by Jeremiah S. Chechik. National Lampoon's Christmas Vacation:  The film stars Chevy Chase, Beverly D'Angelo and Randy Quaid, with Juliette Lewis and Johnny Galecki as the Griswold children Audrey and Rusty, respectively. Johnny Galecki: John Mark Galecki (born April 30, 1975) is an American actor. Johnny Galecki:  He is known for playing David Healy in the ABC sitcom "Roseanne" from 1992 to 1997 and Dr. Leonard Hofstadter in the CBS sitcom "The Big Bang Theory" since 2007.
The Big Bang Theory