Sheldon: (Knocking at Penny's door) Penny! Penny! Penny! Penny! Penny! Penny! Penny! Penny! Penny! Penny! Penny! Penny!
Penny: What the hell is wrong with you?
Sheldon: I'm the Flash, I just knocked 30 thousand times.

Stuart: Can you please get back to the drunk girl, I'd like something to think about in the shower.
Zack: Oh, yeah, right. Anyway, she takes off all her clothes, climbs in the hot tub, and the first thing I noticed--
Sheldon: The water level rose.

Sheldon: What are you talking about?
Leonard: The cultural paradigm in which people have sex after 3 dates.
Sheldon: I see. Now, are we talking date the social interaction or date the dried fruit?

Sheldon: There once was a brave lad named Leonard.
With a fi fi fiddle dee dee.
He faced a fearsome giant.
While Raj just wanted to pee.

Leonard: Hey, where've you been?
Sheldon: I was talking with Penny.
Howard: What's wrong with you? You can't hang out with your roommate's ex. That's totally uncool.
Leonard: No, it's fine. I don't care. I'm over it.
Raj: Yeah, he's over it; that's why he's been whining all day about trying to invent that memory-wiper gizmo from Men in Black.
Sheldon: Is he making any progress? Because I'd like to erase Ben Affleck as Daredevil.
Howard: So would Ben Affleck.

Sheldon: I do not have to urinate. I am the master of my own bladder. Drat.

Sheldon: If ifs and buts were candies and nuts, we would all have a merry Christmas.

Sheldon: Well, I enjoyed that more than I thought I would.
Amy: Me too!
Sheldon: I look forward to your next birthday when we do it again!
Amy: That works for me.

Leonard: I get that you feel bad about all the attention, but still what you did is amazing. We're really proud of you.
Amy: I'm not.
Sheldon: You're not?
Amy: Sheldon, I've been thinking about it and you're right. You don't deserve any credit. All you did was misread some numbers on a table. A very easy table, too. Honestly, I'm embarrassed for you.
Sheldon: That's the most romantic thing I've ever heard.
Penny: Damn it, everyone's better at this than me.
Sheldon: Congratulations, Dr. Fowler. You just made the fort.

Sheldon: Biologically speaking, Howard is perfectly justified in seeking out the optimum mate for the propagation of his genetic line. Howard: Thank you, Sheldon. Sheldon: And whether that propagation is in the interest of humanity is, of course, an entirely different question.

Howard: You gotta like this: the girlfriend, the ex-girlfriend, bonding over your rooty-tooty stinky booty? (All but Leonard laugh)
Leonard: Kill me.
Sheldon: It wouldn't help. The human body is capable of being flatulent for hours after death.

Sheldon: If I would give you this gift basket, based on that action alone and no other data, infer and describe the hypothetical relationship that exist between us.
Store Clerk: Excuse me?
Sheldon: Here. Now, are we friends? Colleagues? Lovers? Are you my grandmother?
Store Clerk: I don't understand what you're talking about and you're making me a little uncomfortable.
Howard: See? Sounds just like you and Penny. We'll take it.

Sheldon: You are effectively paying yourself five dollars and nineteen cents a day.
Penny: A day?
Sheldon: There are children working in sneaker factories in Indonesia who out-earn you.

Sheldon: You can lead a chicken to crisco, but you can't make your mother fry it.

Penny: I finally convinced the restaurant to give me a bar-tending shift, so I need to practice mixing drinks.
Leonard: That's Great! The key to acquiring proficiency in any task is repetition.
Sheldon: With certain obvious exceptions. ... Suicide, for example.