Johnny Galecki is a Belgian-born American actor, best known for his roles as David Healy in Roseanne, Rusty Griswold in National Lampoon's Christmas Vacation, and as Leonard Hofstadter in The Big Bang Theory.
Live in Front of a Studio Audience: Welcome Back, Kotter
Gabe Kotter returns to his old high school -- this time as a teacher. He's put in charge of a class full of unruly remedial students called the Sweathogs. They're a bunch of wisecracking, underachieving and incorrigible students, and it takes all of Mr. Kotter's humor -- and experience as a former Sweathog himself -- to deal with his class.
