Series 5 Episode 12
When Sheldon is dismissive of Amy's career, Penny, Raj and Leonard teach him that sometimes it's a good idea to pretend to care about things
Series 5 Episode 1
The Skank Reflex Analysis: Penny worries that she's screwed things up with her friends after her night with Raj
Series 5 Episode 1
Series 5 Episode 2
The Infestation Hypothesis: A battle of wills between Sheldon and Penny leaves Amy in the middle
Series 5 Episode 2
Series 5 Episode 3
The Pulled Groin Extrapolation: Leonard goes as Amy's date to a colleague's wedding
Series 5 Episode 3
Series 5 Episode 4
The Wiggly Finger Catalyst: Raj is upset that he's not in a relationship, so Penny tries to find him the perfect date
Series 5 Episode 4
Series 5 Episode 5
The Russian Rocket Reaction: Sheldon's old nemesis Wil Wheaton returns and invites everyone to a house-warming party
Series 5 Episode 5
Series 5 Episode 6
The Rhinitis Revelation: Sheldon's mum becomes a firm favourite with his friends - much to Sheldon's annoyance
Series 5 Episode 6
Series 5 Episode 7
The Good Guy Fluctuation: The gang play Halloween pranks on Sheldon. Leonard questions his feelings for Priya.
Series 5 Episode 7
Series 5 Episode 8
The Isolation Permutation: Amy learns that Penny and Bernadette have been shopping for bridesmaids gowns without her
Series 5 Episode 8
Series 5 Episode 9
The Ornithophobia Diffusion: Leonard and Penny attempt to hang out without anybody else around
Series 5 Episode 9
Series 5 Episode 10
The Flaming Spittoon Acquisition: Stuart from the comic book shop asks Amy out, so Sheldon asks her to be his girlfriend
Series 5 Episode 10
Series 5 Episode 11
The Speckerman Recurrence: Leonard confronts the man who bullied him in high school
Series 5 Episode 11
Series 5 Episode 12
The Shiny Trinket Maneuver: Sheldon's friends try to show him that sometimes it's good to pretend to care about things
Series 5 Episode 12
Series 5 Episode 13
The Recombination Hypothesis: In the 100th episode, Leonard and Penny try to give their relationship another chance
Series 5 Episode 13
Series 5 Episode 14
The Beta Test Initiation: Leonard and Penny give their relationship a beta test. Sheldon and Amy seek internet fame.
Series 5 Episode 14
Series 5 Episode 15
The Friendship Contraction: Leonard decides he needs to break the roommate agreement
Series 5 Episode 15
Series 5 Episode 16
The Vacation Solution: When Sheldon's told he has to take holiday, he helps Amy in her biology lab
Series 5 Episode 16
Series 5 Episode 17
The Rothman Disintegration: Amy buys Penny some art to celebrate their friendship
Series 5 Episode 17
Series 5 Episode 18
The Werewolf Transformation: Sheldon's meticulously organised world is turned upside down when his barber is taken ill
Series 5 Episode 18
Series 5 Episode 19
The Weekend Vortex: Amy is upset when Sheldon breaks his promise to accompany her to her aunt's birthday party
Series 5 Episode 19
Series 5 Episode 20
The Transporter Malfunction: Penny buys Star Trek memorabilia for Leonard and Sheldon but they won't open the packaging
Series 5 Episode 20