Played By: Johnny Galecki

Johnny Galecki first rose to prominence for his role as David on the series Roseanne. However, his big breakthrough came when he was cast as Leonard in the Big Bang Theory. In the show, he played the conventional scientist to Sheldon and his array of quirks. Whenever he’s not filming, Galecki also performs in a duet band.

Believe it or not, Galecki also got Leonard’s dream girl for a while. He and co-star Kaley Cuoco from 2007 to 2009 while working on the show. Not only that, but he also dated his on-screen love interest Sara Gilbert while they were both working on Roseanne. Yes, that’s the same Sara Gilbert who portrayed Lesley Winkle. Hey, it seems like Galecki really knows how to handle a breakup!