We don't know where Johnny Galecki's career would be if it hadn't been for 'The Big Bang Theory,' but then we also don't know if 'The Big Bang Theory' would have been such a success if it wasn't for Galecki, so the two things together worked out for the best. Because so much of his appearance in the popular sitcom is the work of the costume department, it's not always easy to spot him when he's out of character. He's actually racked up a few movie credits over the years, including the ill-fated Will Smith superhero movie 'Hancock.'
He's so strongly associated with the show that for a lot of people, he'll probably always be Leonard. We imagine that doesn't bother him all too much - it's believed he was being paid just under $1m per episode for the final season, so he probably never has to work again if he doesn't want to. Not bad for a guy who was once told he was too short to make it as an actor, at 5 foot 5.