Date of birth:
TV directed by Mark Cendrowski (8 of 15)
When Penny breaks up with her boyfriend, Leonard asks her out on a date.
The Big Bang Theory - S01E17 - The Tangerine Factor
Penny attempts to throw Leonard a surprise birthday party.
The Big Bang Theory - S01E16 - The Peanut Reaction
Leonard, Wolowitz, and Koothrappali become smitten with Sheldon's twin sister.
The Big Bang Theory - S01E15 - The Pork Chop Indeterminacy
A time-machine prop from a classic 1960 movie creates problems for Penny.
The Big Bang Theory - S01E14 - The Nerdvana Annihilation
The guys decide to compete in the university's Physics Bowl.
The Big Bang Theory - S01E13 - The Bat Jar Conjecture
After hearing Penny sing, Leonard lies to avoid seeing her perform.
The Big Bang Theory - S01E10 - The Loobenfeld Decay
Sheldon and Leonard are invited to present their joint findings at a conference.
The Big Bang Theory - S01E09 - The Cooper-Hofstadter Polarization
Koothrappali becomes overwhelmed when his parents arrange a blind date for him.
The Big Bang Theory - S01E08 - The Grasshopper Experiment