The Desperation Emanation - S4-E5
Leonard: What about you, Stuart? You have a girlfriend yet?
Stuart: Oh, yeah. Yeah. I met her at Comic-Con, the one place in the world where saying I own a comic book store is an actual pickup line.
The Agreement Dissection - S4-E21
Sheldon: You may have gone to Cambridge, but I am an honorary graduate of Starfleet Academy.
The Zazzy Substitution - S4-E3
Sheldon: May I point out that for eight long months, I suffered in silence as your female companion filled our apartment with her off key country music caterwauling, the unappetizing spectacle of grinding a pommel stone against her calloused feet in our living room, and night after night of uninformative TV documentaries about the Jersey Shore.
Leonard: Suffered in silence?
Sheldon: Yes, and I would expect you to do the same.
Leonard: Really? SILENCE!?
The 21-Second Excitation - S4-E8
Bernadette: I really love Howard's chest hair.
Penny: Howard has a hairy chest?
Bernadette: No, just the one, but it's really long.
Chosen answer: It does. The variable cleanliness of the cab and the habit of taxi drivers to engage customers in small talk would be too much for Sheldon to handle, and not an option for him.
Captain Defenestrator