Sheldon: Do you think your father's doing unspeakable things to my mother?
Leonard: No.
Sheldon: Are you saying that because the things are unspeakable?
Penny: Your parents are old. Anything unspeakable was finished by 9:30.

Sheldon: Here's an interesting fact about alcohol: Man is not the only species that ferments fruit in order to become intoxicated. Can you guess what the other is? Hint: sometimes they pack the alcohol in their trunks.
Penny: Monkeys.
Sheldon: When does a monkey have a trunk?
Penny: When a suitcase just won't do.

Penny: Sheldon, that's not what girlfriends are for. Although you don't use them for what they're for, so what do I know?

Penny: Don't you dare knock!

Leonard: Wow, Penny, you're on fire!
Penny: Yeah, so is Sheldon!

Leonard: Don't you think if a woman was living with me I'd be the first one to know about it?
Penny: Oh, sweetie, you'd be the last one to know about it.

Leonard: Before you say anything, have you heard of Schrodinger's cat?
Penny: Actually, I've heard far too much about Schrodinger's cat.
Leonard: Good.
*Leonard and Penny kiss*
Penny: All right, the cat's alive. Let's go to dinner.

Leonard: They're gonna get beaten up at that club.
Penny: They're gonna get beaten up at Walgreens.

Penny: And what kind of doctor removes shoes from asses?

Penny: Did Sheldon change the Wi-Fi password again?
Leonard: Yeah, it's "Penny already eats our food she can pay for Wi-Fi". No spaces.

Penny: Holy crap on a cracker!

Raj: Ooo.
Penny: What's the matter, Lassie? Did Timmy fall down the well?

Penny: (To Howard and Raj) So either one of you weirdos wanna buy my underwear? Only 1400 bucks.

Penny: I'm a vegetarian, except for fish, and the occasional steak. I LOVE steak!
Sheldon: Well, that's interesting. Leonard can't process corn.

Penny: I'm sorry, shoes, but you have to go back.
Shoebox (Penny): But, Penny, we love you.
Penny: I love you, too, but you cost more than my rent.
Shoebox (Penny): But Penny, you look so good in us.
Penny: (To Amy) Damn it, the shoes are right!