Leonard: I'm sorry.
Raj's sister: Why do you say that?
Leonard: When I'm in bed with a girl, that's just my natural response.

Raj: Hands off my sister.
Sheldon: Why would I touch your sister? She's all covered in airplane germs.

Sheldon: And to think, I was about to waste the last of my good haemorrhoid cream on you.

Raj: I can't believe you kissed my sister with moth mouth.
Leonard: Well, I can't believe you'd use Sheldon's toothbrush.
Sheldon: You used my toothbrush?
Raj: Not the brush part. Just the little rubber thing to pick food from my teeth and massage my gums.

Raj: You slept with my sister?
Leonard: Yeah?
Howard: How could you? We had a pact.
Raj: Excuse me, I think "How could you, she's my sister" takes precedence over a 5-year-old pinkie swear.

Sheldon: I always tell people, if you have only one day in Los Angeles, make it a train day.
Raj: "Train Day?"
Sheldon: The fun starts with brunch at Carney's in Studio City, a hot dog stand in a converted railroad dining car. Next stop, Travel Town, an outdoor museum featuring 43 railroad engines, cars, and other rolling stock from the 1880s to the 1930s. Then finally, we're off to the glitz and glamour of Hollywood, for dinner at, that's right, the Hollywood Carney's, a hot dog stand in a different converted railroad dining car.
Raj: I don't think we're gonna do that.
Sheldon: Well, then apparently, you hate fun.

Leonard: Okay fine, I'm-I'm a horrible human being. I'm the Darth Vader of Pasadena.
Sheldon: You're far too short to be Darth Vader. At best you might be a turncoat Ewok.

Sheldon: It's a shame our society mocks the differently uvulated.

Howard: This is the worst cobbler I've ever eaten. It tastes like it's made of actual ground-up shoemaker.
Sheldon: Amusing. A play on the two meanings of cobbler.

Sheldon: Do you like trains?
Priya: Not particularly.
Sheldon: You might as well just wait at the airport for your flight.

Leonard: Really? You're going to risk getting sleepy in the middle of your themodynamic fluctuations seminar? You know what happens when you yawn in public.
Sheldon: Everyone will see my oddly shaped uvula.

Raj: Hey, so what did you guys think of the new episode of Caprica last night?
Leonard: I didn't see it.
Howard: Didn't see it? What were you doing?
Leonard: Uh, I was out.
Raj: On Caprica night?
Leonard: Yeah, I, uh, went for a drink.
Howard: Really, you, and where, where did you go?
Leonard: To, uh, Lucky Baldwin's.
Sheldon: Oh, I've heard of that place. Isn't that Pasadena's favorite Irish watering hole?
Leonard: Yes.
Sheldon: Did you meet anyone interesting there, perhaps a promiscuous redheaded barmaid?
Leonard: As a matter of fact I-I-I can't. I can't. I can't do it.

Sheldon:(typing) Hit troll with axe! Hit troll with axe! Hit troll with axe! Oh, my, this is one tough troll.

Howard: I have a girlfriend now.
Priya: Hey, good for you.
Howard: Yeah, I just wanna put it out there in case I inadvertently squirt any pheromones in your direction.

Leonard: Sorry.
Priya: For what?
Leonard: I don't know. When I'm in bed with a girl, it's just it's my go to response.