Successful ensemble sitcoms often seem to have one actor or actress who breaks away from the rest of the cast in popularity and attention. Jennifer Aniston in Friends and Neil Patrick Harris of How I Met Your Mother (HIMYM) are two examples.

The Big Bang Theory premiered on September 24, 2007 with five main characters and has enjoyed success on CBS Monday Nights along with the aforementioned HIMYM and Two and a Half Men. Recently renewed for two more seasons, The Big Bang Theory was recently moved to 9:30 p.m. following Two and a Half Men for their third season.

The cast member who seems to be rising to the top is recent Emmy nominee, Jim Parsons. The 6'2" actor from Houston, Texas plays the part of Sheldon Cooper, Ph.D., a theoretical physicist with two Ph.D.s and an IQ of 187. He previously enjoyed a recurring role on Judging Amy.

On The Big Bang Theory, he shares an apartment with Leonard Hofstadter, Ph.D. played by Johnny Galecki, an experimental physicist with an IQ of 173.

Two of their friends include Howard Wolowitz, M.Eng. portrayed by Simon Helberg. The character works as an engineer and lives with his mother although he is seen quite often at their apartment. He is Jewish and the only one of the four that does not have a Ph.D., but likes to remind people he has a Masters in Engineering from MIT.

Kunal Nayyar plays their friend Rajesh Koothrappali, Ph.D. who works as a Particle Astrophysicist at Caltech. He is originally from India, and is so shy he cannot speak in front of women.

Another important member of the cast is Kaley Cuoco who plays aspiring actress Penny. She lives across the hall from Sheldon and Leonard, and is a waitress at the local Cheesecake Factory. Raised on a farm in Nebraska, Penny is the only one without a degree but seems to get along fairly well with the guys.

An attractive blond, Penny’s common sense contrasts with the weird, geeky men across the hall. She and Leonard have shown an affection for one another that give off occasional sparks between the two. Sheldon’s lack of humility often brings a strong reaction from Penny and the two have quite a contentious relationship.

An important recurring character of the show is Sara Gilbert as Leslie Winkle, Ph.D., an experimental physicist. Although she has slept with both Leonard and Howard, she does not get along with Sheldon.

Much of the show’s premise focuses on the relationships of the characters among one another, how they bounce ideas off each other, and the crazy schemes they seem to come up with.

The Big Bang Theory was created and produced by Chuck Lorre and Bill Prady, and has proven to be a worthy entry in the Monday night mix. With Parsons leading the way, the talented ensemble cast could enjoy quite a long run as another successful sitcom.