Penny: I'm a Sagittarius, which probably tells you way more than you need to know.
Sheldon: Yes, it tells us that you participate in the mass cultural delusion that the sun's apparent position relative to arbitrarily defined constellations at the time of your birth somehow affects your personality.
Penny: (puzzled) Participate in the what?

Leonard: We need to widen our circle.
Sheldon: I have a very wide circle. I have 212 friends on MySpace.
Leonard: Yes, and you've never met one of them.
Sheldon: That's the beauty of it.

Sheldon: What if she ends up with a toddler who doesn't know if he should use an integral or a differential to solve for the area under a curve?
Leonard: I'm sure she'll still love him.
Sheldon: I wouldn't.

Penny: I'm so sorry. I really thought if you guys went instead of me, he wouldn't be such an ass.
Leonard: No, it was a valid hypothesis.
Sheldon: "Was a valid hypo-" . What is happening to you?

Leonard: Our babies will be smart and beautiful.
Sheldon: Not to mention imaginary.

Penny: So, what do you guys do for fun around here?
Sheldon: Well, today we tried masturbating for money.

Leonard: I love cheesecake.
Sheldon: You're lactose-intolerant.
Leonard: I don't eat it. I just think it's a good idea.

Sheldon: I don't know what your odds are in the world as a whole but as far as the population of this car goes you're a veritable mack daddy.

Penny: Would it be weird if I used your shower?
Leonard: No.
Sheldon: Yes.
Leonard: (to Sheldon) No!
Sheldon: No?
Leonard: No!
Sheldon: (to Penny) No.

Leonard: Come on! We have a combined IQ of 360 we should be able to figure out how to get into a stupid building.
*Two girls selling cookies ring every bell, the door opens*
Sheldon: What do you think their combined IQ is ?

Leonard: New neighbor?
Sheldon: Evidently.
Leonard: Significant improvement over the old neighbor.
Sheldon: A 200 pound transvestite with a skin condition, yes, she is.

Leonard: What makes you think she wouldn't have sex with me? I'm a male and she's a female.
Sheldon: Yes, but not of the same species.

Penny: Oh, anyways I'm also writing a screenplay. It's about this sensitive girl who comes to LA from Lincoln, Nebraska, to be an actress and who ends up a waitress at the cheesecake factory.
Leonard: So it's based on your life?
Penny: No, I'm from Omaha!

Sheldon: My mom bought me those pants.
Leonard: I'm sorry!
Sheldon: You're gonna have to call her.

Sheldon: So, if a photon is directed through a plane with two slits in it and either is observed, it will not go through both. If it's unobserved, it will. However, if it's observed after it left the plane, before it hits it's target, it will not have gone through both slits.
Leonard: Agreed! What's Your Point?
Sheldon: There's no point, I just think it's a good idea for a T-shirt!