Amy: If I may, I'd like to propose a toast. Um, thank you all for coming tonight. I know it's customary for the birthday boy to receive presents, but I feel like I got the greatest gift the day he was born.
Everybody: Aww.
Raj: Hear, hear.
Sheldon: Amy, that was lovely. You know, this is fun. Let's do more. Someone else say something wonderful about me.

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.

Leonard: What would I even say?
Sheldon: "Zack, I'm sorry you're stupid. Have a Milk Dud."
Raj: A Milk Dud?
Sheldon: Yeah, Milk Duds, with their self-deprecating name and remarkably mild flavor, are the most apologetic of the boxed candies.
Leonard: I got a better idea. Were all responsible. I say we all go. Come on, who's with me? Free comic books to anyone who comes with me. I might get punched. You really want to miss that?
Raj: Junior Mints are pretty apologetic.
Sheldon: You're embarrassing yourself.

Sheldon: That's not afternoon. That's prevening.
Howard: What?
Sheldon: It's a time of day I invented. It better defines the ambiguous period between afternoon and evening. Prevening. I'm fairly certain it will catch on as it fills a desperate need.
Raj: Right, okay. What are you doing tomorrow prevening?
Sheldon: Well, tomorrow's Saturday. Saturday night is laundry night, so I'll be spending the prevening pre-sorting and pre-soaking.

Sheldon: And look over here, "shrimp in mobster sauce". What is mobster sauce?
Leonard: It's obviously a typo.
Sheldon: Perhaps. Perhaps this restaurant's now a front for organized crime. For all we know, the mobster sauce contains actual chunks of deceased mobsters.
Raj: No, no, no, no. I think it jut means it's the kind of sauce that mobsters like.
Howard: It doesn't mean any of that. It's a typo!

Sheldon: Leonard, as soon as we get home, I want to have coitus with Amy. [checks for Amy's reaction] Okay, she can't hear.

Sheldon: I feel renewed. I'm ready to deal with any changes that come my way. [sees Penny] Your hair is different. You changed your hair. I can't take this. I'm out.

Sheldon: We no longer live at 2311 Los Robles. We live at 311 Los Robles. [holds up number 2 fixture]
Leonard: You changed the address on the building? What about mail?
Sheldon: No worries. I explained our predicament to our letter carrier. He was sympathetic. His exact words were, "Got your back, Jack. Bitches be crazy."

Penny: You were acting?
Sheldon: Yes. In preparation for today's studies, I read Stanislavski's An Actor Prepares, Stella Adler's The Technique of Acting, Uta Hagen's Respect for Acting, and Henry Winkler's Ey!, I'm an Actor.

Sheldon: The entire institution of gift giving makes no sense. Let's say that I go out and I spend 50 dollars on you. It's a laborious activity because I have to imagine what you need whereas you know what you need. Now I could simplify things, just give you the 50 dollars directly and then you could give me 50 dollars on my birthday and so on, until one of us dies leaving the other one old and 50 dollars richer. And I ask you is, it worth it?

Sheldon: What is the best number? By the way, there's only one correct answer.
Raj: 5,318,008?
Sheldon: Wrong. The best number is 73. [short silence] You're probably wondering why.
Leonard & Howard: No, no, we're good.
Sheldon: 73 is the 21st prime number, its mirror 37 is the 12th and its mirror 21 is the product of multiplying, hang on to your hats, 7 and 3. Did I lie?
Leonard: We get it. 73 is the Chuck Norris of numbers.
Sheldon: Chuck Norris wishes. In binary, 73 is a palindrome, 1001001, which backwards is 1001001, exactly the same. All Chuck Norris gets you backwards is Sirron Kcuhc.
Raj: Just for the record, when you enter 5,318,008 in a calculator, upside down it spells boobies.

Sheldon: Under normal circumstances I'd say I told you so. But, as I have told you so with such vehemence and frequency already, the phrase has lost all meaning. Therefore, I will be replacing it with the phrase, "I have informed you thusly".

Bernadette: Sheldon, when was the last time you got any sleep?
Sheldon: I don't know. 2 or 3 days. Not important. I don't need sleep, I need answers. I need to determine where in this swamp of unbalanced formulas squatteth the toad of truth.
Penny: Toad of truth? Is that a physics thing?
Leonard: No, that's a crazy thing.

Leonard: She's not going to steal our idea.
Penny: What idea?
Leonard: We're gonna write an application...
Sheldon: [sings] The prairie sky is wide and high, deep in the heart...
Penny: Okay, stop, stop!
Sheldon: [meekly] ...of Texas.