Season 4, Episode 12: The Bus Pants Utilization.

Season 5, Episode 16: The Vacation Solution.

Season 5, Episode 9: The Ornithophobia Diffusion.

Season 4, Episode 24: The Roommate Transmogrification.

Season 1, Episode 1: Pilot Episode.

The Big Bang Theory recieves 7 Emmy Nominations.

Season 4, Episode 3: The Zazzy Substitution.

Season 4, Episode 18: The Prestidigitation Approximation.

Season 4, Episode 7: The Apology Insufficiency.

Seasons 6 & 7: the build-up to the first Sheldon initiated kiss.