Big Bang Theory, A CBS Sit-com

Leonard
The classic chic geek with low self-esteem but a really sweet personality. Leonard has all the appeal of guy-next-door instant-best-friend. Unfortunately, he wants to be more than just friends with the girl next door.

Sheldon
His uber-intelligence coupled with his early achievements has left his character sadly lacking in both humility and social skills. But what he lacks in empathy for others, he often makes up for with his quick wit.

Wolowitz
Ah, the geek who has no clue he has no chance. With an eternal sense of hope, Wolowitz exudes a presence similar to Steve Urkel of Family Matters from back in the day. But Wolowitz does not have his eyes set on any specific girl- just about anything female will do.

Rajesh
Oh, the strong/silent type! At least, that's what all the girls think. This poor guy cannot find words in the presence of female company. What does it take for him to loosen his lips? Apparently alcohol!

Penny
The cute but flaky girl next door who very quickly becomes the object of Leonard's affections. While the guys may all suffer from social awkwardness, Penny is a social butterfly. As such, she offers lots of advice and an outsider's perspective to the dialog.

The opening scene of the pilot episode shows Leonard and Sheldon in the waiting room of a sperm bank. Their discussion reveals that they are very intelligent physicists who have approximately zero social skills. They quickly back out and head back to the apartment they share, where they notice an attractive young blond has moved in across the hall. Leonard instantly has a crush on her, so he introduces himself, finds out her name is Penny, and invites her over. Leonard and Sheldon's friends, Wolowitz and Koothrappali, swing by the apartment while Penny is still there. This gives her a chance to see the geeks in all their awkward glory. Before leaving, she asks for a favor, and since Leonard has completely lost the capacity to formulate rational thoughts in her presence, he agrees to go to her ex-boyfriend's apartment to get her tv. Hilarity ensues.

When Sheldon and Leonard stop by Penny's to drop off a package that came for her, they find a terrible surprise inside. Penny is a slob! Sheldon deems this unacceptable and sneaks back in later while Penny is sleeping to clean and organizes. Needless to say, Penny was none too happy.

Leonard is disheartened to see Penny kissing another guy in the hallway. So, to cheer him up and get his mind off of his recent rejection, the guys convince him to ask a coworker out. Unfortunately, she is equally geeky with about the same set of social skills and rejects him. The guys try to cheer him up a little more, but ultimately he decides to ask Penny out to dinner. Ah, awkward geek love, bittersweet on so many levels!

Sheldon's pride gets him fired from his job at the university. This change sends this OCD into a terrible depressed frenzy. They guys try to reason with him, to help him through the rough time, but they end up having to call in the big guns: Sheldon's mom. She's absolutely nothing like Sheldon, but she knows him best and her visit does the trick. I heart geek moms! They put up with so much.

In a nutshell: drama! Basically, Leonard ends up hooking up with Leslie, the girl from his work who had previously rejected him. Sheldon finds out and mentions it to Penny. Leonard is upset over Penny knowing and then feels rejected when he finds out all Leslie wanted was a one night stand. Geesh! When will poor Leonard get a break!

Halloween party at Penny's! Imagine the awkwardness that follows when four geeks who dress in preparation for Comic Con are invited to party with a room full of social butterflies who think Halloween is an excuse to get drunk and hook up. Yeah, that's awkward! Oh, and Leonard gets a kiss.

Penny's slutty friend comes to town and takes advantage of Wolowitz. In order to avoid the extremely uncomfortable situation presenting itself in her own apartment, Penny decides to stay with Leonard and Sheldon for a little bit. Their whole little world is turned upside down as a result.

Koothrappali, who is incapable of speaking to girls, is set up on a date with his Indian parents. Penny happens to be studying to become a bartender to increase her earning potential at work and by sheer coincidence, the group discovers that alcohol is the key to helping their Indian friend loosen up around women. The date, however, still bombs. Believe it or not, she is more interested in Sheldon! Who could have predicted that turn of events?!

Sheldon and Leonard are invited to present joint findings at a local physics conference. Sheldon refuses but Leonard decides to present without him, and when Penny tries to help, things take a turn for the worse.

Penny is offered a one night spot in a production of RENT. Unfortunately, she is a terrible singer. To avoid the obligatory false compliments, Leonard opts to lie to Penny when she invites him to the show. Sheldon, however, is positive that she may find out, so he elaborates and convolutes the lie into a terrible mess that leaves the guys with a road trip, tourist gear and a "homeless drug addict" for a new roommate. It's a must-see to believe kind of episode.

Sheldon, the germophob, gets sick and, like every good germophob, he instantaneously devolves into a whiny hull of a man. All his friends have experienced this side of Sheldon before and institute their plan to stay out of dodge for the next 42-78 hours. By default, Sheldon turns to Penny for comfort. The result is tons of awkward moments and a sneak at the pathetic, weaker side of Sheldon that not even his truest friends want to endure.