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: Participate in the what?

Sheldon: [to Leonard] 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.

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.

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

Althea: Fill these out.
Leonard: Thank you. We'll be right back.
Althea: Oh, take your time. I'll just finish my crossword puzzle. Oh wait.

Leonard: I'm gonna invite her (Penny) over. We'll have a nice meal and chat.
Sheldon: Chat? But we don't chat, at least not off-line.

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.

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.

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

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!

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: (Helping Althea with the crossword puzzle) One across is Aegean, eight down is Nabokov, 26 across is MCM, fourteen down is-- move your finger, phylum, which makes 14 across Port-au-Prince. See, Papa Doc's capital idea, that's Port-au-Prince. Haiti.