"Four seasons in, it is still laugh-out-loud funny. Every episode, every week," says USA Today's Robert Bianco about the hit series The Big Bang Theory. Subject his conclusion to empirical analysis by watching all 24 Episodes of Season Four on 2 Discs. This season, the Big Bang gang's romantic universe expands. On the rebound from Penny, Leonard falls for Raj's sister Priya. Sheldon gets a girlfriend - Amy, a dour neurobiologist who declares herself Penny's BFF. Howard and Bernadette heat up; meanwhile, Raj is romancing her in Bollywood daydreams. Observe all the forces of attraction in this genius, award-winning comedy.

Episodes:
1. The Robotic Manipulation
2. The Cruciferous Vegetable Amplification
3. The Zazzy Substitution
4. The Hot Troll Deviation
5. The Desperation Emanation
6. The Irish Pub Formulation
7. The Apology Insufficiency
8. The 21-Second Excitation
9. The Boyfriend Complexity
10. The Alien Parasite Hypothesis
11. The Justice League Recombination
12. The Bus Pants Utilization
13. The Love Car Displacement
14. The Thespian Catalyst
15. The Benefactor Factor
16. The Cohabitation Formulation
17. The Toast Derivation
18. The Prestidigitation Approximation
19. The Zarnecki Incursion
20. The Herb Garden Germination
21. The Agreement Dissection
22. The Wildebeest Implementation
23. The Engagement Reaction
24. The Roommate Transmogrification