Leonard Hofstadter (Johnny Galecki) from "The Big Bang Theory" is the best friend and housemate of Sheldon Cooper (Jim Parsons). Sheldon is obnoxious, has a superiority complex, and generally drives everybody he meets crazy. Not only does Leonard have to live with Sheldon, but he also has to deal with Sheldon at work. The two work together as physicists with their friends Howard Wolowitz (Simon Helberg) and Raj Koothrappali (Kunal Nayyar). Leonard is one of the most likeable characters on the show, and he has the desire to be as normal as possible. However, due to the people he has as friends, he is branded a nerd. In addition to this, Leonard does not really know how to be a "normal" person, but he has trouble embracing the fact that he is indeed a nerd.
Although many of the episodes of "The Big Bang Theory" can be watched in any order, an ongoing storyline in the show is Leonard's pining for the girl that lives next door named Penny (Kaley Cuoco). Penny wants to get into show business, but instead she works at the Cheesecake Factory and never has enough money to even make the rent. She constantly takes advantage of Leonard's kindness by taking his money, but she is not a malicious character. Penny dates Leonard for a brief period in the show, but she decides to break it off with him after he expresses his love for her. Penny does not know what she wants in a romantic relationship, and this frustrates Leonard a great deal. Leonard also had a brief relationship with Leslie Winkle (Sara Gilbert), another one of his coworkers.
Leonard is a main character in "The Big Bang Theory", but Sheldon is the main character of the show. However, Leonard is an important character because he keeps Sheldon in check when Sheldon is about to do something crazy. His interactions with Sheldon are hilarious and really make the show what it is. Sheldon also needs Leonard when he becomes upset about something. One such time was when Sheldon ate too many Brussel sprouts and thought his appendix was going to explode, so Leonard offered to take Sheldon to the hospital. He puts up with Sheldon when the other characters won't.
In a recent episode, Penny asked Leonard to pretend to be her boyfriend because she lied to her father (Keith Carradine) and told him she was dating Leonard. After finding out that it was a lie, he begged Leonard not to give up on his daughter. Penny seems to have feelings for Leonard that she will not come to terms with. Will Penny and Leonard end up together?
"Would someone please turn off the Sheldon commentary track?"
"Homo habilis discovering his opposable thumbs says what?"
"Hi. I'm Leonard. You are beautiful. You pop, sparkle and buzz e-lec-tric. I'm going to pick you up at eight, show you a night you will nev-er for-get."
"12 years after high school and I'm still at the nerd table."