Penny: Don't you dare knock!

Penny: You gotta help me get my arm into my sleeve.
Sheldon: (Eyes closed) Okay!
Penny: Is that my arm?
Sheldon: It doesn't feel like an arm.
Penny: Then maybe you should let it go.

Penny: Sing Soft Kitty to me.
Sheldon: Soft Kitty is for when you’re sick. You're not sick.
Penny: Injured and drugged is a kind of sick.
Sheldon: [sings] Soft kitty, warm kitty, little ball of fur…
Penny: Wait, wait. Let's sing it as a round. I'll start. [sings] Soft kitty, warm kitty, little ball of fur… See that's where you come in. I'll start over. [sings] Soft kitty, warm kitty, little ball of fur… I've got all night, Sheldon. Soft kitty, warm kitty…
Both: [sing] ...little ball of fur, happy kitty, sleepy kitty, purr, purr, purr.

Leonard: Well, I can't read your mind, Penny!
Penny: Really? Why not? You're so smart, and I'm so dumb.

Penny: All right, five. One, two, three, four, five. Oh, wow, look at that, my Department of Defense research grant is renewed.
Sheldon: Oh! Great roll! Now you can demolish your Soviet-style cyclotron and build the large Hadron Collider.
Penny: Yay.

Penny: Oh, thank you very much. Come back soon. With the other half of my tip.

Penny: You know, how about we buy you this robot, and then we all go home?
Sheldon: I want that one.
Penny: Okay, you can have that one.
Leonard: Oh, come on, he's just going to play with it twice, and then it'll end up in his closet with all the other junk.
Penny: Buy him the robot, Leonard.
Sheldon: Can I get this comic book, too?
Penny: Yes, you can.

Penny: Here, have some pizza, sweetie.
Leonard: You know I'm lactose intolerant.
Penny: I know; I just need you to stop talking.

Penny: Sheldon, come in.
Sheldon: Thank you. I'd like to make a sandwich, but I'm out of bread.
Penny: There's some in the fridge.
Sheldon: You shouldn't keep your bread in the refrigerator. Staleness is caused by crystallization of the starch molecules, which occurs faster at cool temperatures.
Penny: On Earth, we say thank you.

Leonard: A long time ago, I made a deal with Howard involving you.
Penny: Okay, I don't know where this is going, but tread carefully, because this may be the last conversation we ever have.

Penny: The great thing about Ernie (Sesame Street Puppet) is that he didn't ask for anything, he just gave.

Penny: (About the cards) I got a question.
Leonard: Warlord beats troll, troll beats elf, elf beats water sprite, and basically everything beats Enchanted Bunny.
Howard: Unless you have the carrot of power.
Penny: Okay, I've got another question. When does this get fun?

Leonard: You know deep down inside, Howard's a nice guy.
Penny: The problem isn't what's on the inside. It's the creepy candy coating.

Penny: Honey, you don't have to thank me every time we have sex, sweetie.

Penny: Oh, you know, that reminds me. I usually go back to Nebraska for Thanksgiving, but this year they're calling it off on account of my brother's trial.
Leonard: What's he on trial for?
Penny: Oh, just a big misunderstanding. You know, you'd actually like my brother. He's kind of a chemist.