1. The Bad Fish Paradigm

Penny opens up to Sheldon after a less-than-stellar first date with Leonard, pla... More

2. The Codpiece Topology

Seeing Penny with another guy sends Leonard back to Leslie Winkle, much to Sheld... More

3. The Barbarian Sublimation

Penny becomes addicted to an online game based on the world of Conan the Barbari... More

4. The Griffin Equivalency

Full of confidence following being named one of People's 30 to Watch Under 30, R... More

5. The Euclid Alternative

An intervention is used to try to force Sheldon to overcome his fear of driving.

6. The Cooper-Nowitzki Theorem

Sheldon and his friends are mystified when a younger undergraduate student is at... More

7. The Panty Pinata Polarization

Penny retaliates after Sheldon bans her from the apartment for minor infractions... More

8. The Lizard-Spock Expansion

Sheldon wants to use an alternate version of rock-paper-scissors to help resolve... More

9. The White Asparagus Triangulation

Sheldon is over-exuberant that Leonard finally has a girlfriend matching his hig... More

10. The Vartabedian Conundrum

Leonard seeks Penny's counsel when his relationship with Stephanie takes off. Sh... More

11. The Bath Item Gift Hypothesis

Sheldon irks the gangs with his obsession with proper Christmas gift protocol. L... More

12. The Killer Robot Instability

Penny's criticism of Wolowitz's romantic life pushes him into depression and AWO... More

13. The Friendship Algorithim

Looking to get friendly with Barry Kripke to gain access to a piece of high-tech... More

14. The Financial Permeability

When Sheldon loans money to Penny so she can pay her rent, it leads to Leonard c... More

15. The Maternal Capacitance

A visit from Leonard's mother ends up bringing him and Penny closer.

16. The Cushion Saturation

Paintball leads to a squabble between Sheldon and Penny as well as romance betwe... More

17. The Terminator Decoupling

The gang is thrilled when they see Terminator: The Sarah Connor Chronicles' Summ... More

18. The Work Song Nanocluster

Penny's business selling hair accessories out of her apartment gets out of hand ... More

19. The Dead Hooker Juxtaposition

Penny feels threatened when another sexy woman moves into the apartment building... More

20. The Hofstadter Isotope

A fellow comic book enthusiast's hitting on Penny leads to Leonard, Raj and Howa... More

21. The Vegas Renormalization

Leonard and Raj take Wolowitz to Las Vegas to help him get over his break-up. Sh... More

22. The Classified Materials Turbulence

Stuart asks Leonard's advice for a date with Penny. Wolowitz realizes there's an... More

23. The Monopolar Expedition

The guys receive a prestigious offer to work over the summer at the North Pole, ... More