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Leonard and Penny About to Kiss
Watch The Big Bang Theory Season 1 Episode 17
"The Tangerine Factor"
Original Air Date:

Penny breaks up with her boyfriend after he posted intimate details about her on his blog. Leonard tries to comfort her but accidentally sends her back into the arms of her boyfriend.

Wolowitz Distracts Leonard
Watch The Big Bang Theory Season 1 Episode 16
"The Peanut Reaction"
Original Air Date:

When the boys go to eat at Penny's restaurant, she learns Leonard has never had a birthday before. She decides to throw him a surprise party and blackmails Leonard into helping.

Leonard, Wolowitz and Missy
Watch The Big Bang Theory Season 1 Episode 15
"The Porkchop Indeterminacy"
Original Air Date:

The guys meet Sheldon's extremely attractive twin sister Missy (Courtney Henggeler) who is in town for a wedding.

The Boys Gather Round Leonard
Watch The Big Bang Theory Season 1 Episode 14
"The Nerdvana Annihilation"
Original Air Date:

Leonard buys a replica time machine online from the 1960 film The Time Machine and ends up splitting it with the guys.

Leslie and Leonard are PMS
Watch The Big Bang Theory Season 1 Episode 13
"The Bat Jar Conjecture"
Original Air Date:

The guys compete in a physics bowl after the previous contestants dropped out to form a barbershop quartet. When Sheldon's showboating becomes too much for them, they kick him off the team.

The Guys Meet Dennis Kim
Watch The Big Bang Theory Season 1 Episode 12
"The Jerusalem Duality"
Original Air Date:

Sheldon becomes insecure over his intelligence because of a smarter 15-year-old prodigy Dennis Kim. He decides his work is useless and he aims for the Nobel Peace Prize by creating a "Nuevo Jerusalem."

Penny Takes Care of Sheldon
Watch The Big Bang Theory Season 1 Episode 11
"The Pancake Batter Anomaly"
Original Air Date:

Penny returns from a visiting family in Nebraska with a cold causing Sheldon to freak out because he's a bit of a germaphone.

Sheldon and His Cousin
Watch The Big Bang Theory Season 1 Episode 10
"The Loobenfeld Decay"
Original Air Date:

When Penny is given a part in Rent, the boys try to avoid to see her show after hearing her sing "Out Tonight" out of key in order to not hurt her feelings.

Sheldon's Mind Trick
Watch The Big Bang Theory Season 1 Episode 9
"The Cooper-Hofstadter Polarization"
Original Air Date:

After cleaning up after an internet experiment, Leonard discovers a letter in the trash can inviting the roommates to present some research they've done to a physics conference.

Penny Makes Raj Drink
Watch The Big Bang Theory Season 1 Episode 8
"The Grasshopper Experiment"
Original Air Date:

Raj is scared when his parents arrange a blind date for him with a girl from his childhood as he's still unable to women. Penny takes up bar tending to make some extra money.

Penny Plays Halo
Watch The Big Bang Theory Season 1 Episode 7
"The Dumpling Paradox"
Original Air Date:

Penny's slutty friend, Chrissy (Brooke D'Orsay) from Nebraska, is in town and is seduced by Wolowitz. The pair ends up taking over Penny's apartment, forcing her to sleep on Leonard and Sheldon's couch.

Leonard, Sheldon and Raj on the Couch
Watch The Big Bang Theory Season 1 Episode 6
"The Middle-Earth Paradigm"
Original Air Date:

The guys are invited to Penny's Halloween party and decide to go only when the idea of costumes are mentioned. At the party, Wolowitz and Leonard attempt to socialize until Penny's ex, Kurt, shows up and humiliates Leonard.

Penny Explains to Sheldon
Watch The Big Bang Theory Season 1 Episode 5
"The Hamburger Postulate"
Original Air Date:

While eating at the Cheesecake Factory where Penny works, the guys run into Leslie Winkle, the girl who previously rejected Leonard. Leslie asks Leonard to play in her string quartet as the cellist, but what she really wants is him.

Sheldon Gets Fired
Watch The Big Bang Theory Season 1 Episode 4
"The Luminous Fish Effect"
Original Air Date:

Sheldon is fired from his job at Caltech when he insults his boss Dr. Eric Gablehauser. Unemployed, Sheldon quickly spirals into depressions which Leonard tries to end by bringing over Sheldon's mother.

Leonard Asks Out Leslie
Watch The Big Bang Theory Season 1 Episode 3
"The Fuzzy Boots Corollary"
Original Air Date:

When Leonard witnesses Penny kissing a guy in front of their apartment, he is hurt and feels "rejected." The guys try to convince him to ask a girl out at work and when he's rejected by Leslie Winkle, he is even more depressed.

Sheldon and Leonard Deliver
Watch The Big Bang Theory Season 1 Episode 2
"The Big Bran Hypothesis"
Original Air Date:

When Sheldon and Leonard head over to Penny's apartment to drop off a package that arrived for her, Sheldon is bothered by how messy her apartment is.

Sheldon and Leonard
Watch The Big Bang Theory Season 1 Episode 1
"Pilot"
Original Air Date:

In the pilot, life is about to change for two geniuses, Sheldon and Leonard when the beautiful Penny moves in across the hall. Leonard sees potential love interest in Penny and offers to retrieve her television from her ex-boyfriend.

The Big Bang Theory Season 1 Quotes

Penny: What actor holds the record for being named People magazine's Sexiest Man Alive?
Sheldon: William Shatner!
Leonard: I don't think it's Shatner.
Sheldon: Then it's got to be Patrick Stewart

Leonard: We need to widen our circle.
Sheldon: I have a very wide circle. I have 212 friends on MySpace.
Leonard: Yes, and you've never met one of them.
Sheldon: That's the beauty of it

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