Sheldon: Howard, I have to go to the bathroom and no one will take me home.
Howard: What's wrong with the bathroom here?
Sheldon: Pneumococcus, streptococcus, staphylococcus and other assorted cocusses.
Howard: Sheldon, my mother is on her deathbed and my fiance is grief-stricken over putting her there. I'm not taking you home!
Sheldon: Will you at least go with me to the restroom here so you can open the door and flush the urinal?
Howard: No!
Sheldon: This might be a good time to point out, Howard, that friendship requires a certain give and take.

Sheldon: All right, I'll just toss this out to the room. Um, I was thinking that the best way to fight my addiction is by weaning myself off in steps. Now, I couldn't find a caffeine patch, but I did find what claims to be a mind-boosting caffeine suppository. Yeah, you know, there's an interesting fact about the rectum--
Leonard: Sheldon!

[Sheldon moves around the movie theater, sitting in various seats and emitting various noises]
Steph: What is he doing?
Leonard: He's finding the "acoustic sweet spot".
Steph: Does he always do this?
Leonard: Sometimes he brings a toy xylophone. I am really sorry about this.
Steph: No, it's fine. You know, he's sweet.
Sheldon: My apologies, you've been sitting in it all along. Leonard, you want to slide over one?
Leonard: No, just sit here.
[As the movie begins, Sheldon cranes his neck over to experience the sound in Leonard's seat]
Sheldon: Oh, yeah, this is it.

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 just means it's the kind of sauce that mobsters like.
Howard: It doesn't mean any of that. It's a typo!

Sheldon: Mmm. [in Mandarin] Your monkey sleeps inside me.

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: 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?