Sheldon: Yes, since their relationship became carnal, Penny has updated his designated term of endearment, distinguishing him from those she calls 'sweetie,' usually as an attempt to soften a thinly-veiled insult.
Penny: You're boring people, sweetie.
Sheldon: Although sometimes, she omits the veil entirely.

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.

Sheldon: Pee for Houston, pee for Austin.
Pee for the state my heart got lost in.
And shake twice for Texas.

Sheldon: I should've brought an umbrella.
Leonard: What for? It's not going to rain.
Sheldon: I know that, but with skin as fair as mine, moon burn is a real possibility.
Howard: That's a bazinga, right?
Sheldon: One of my best, don't you think?

Sheldon: I would point out that I am at the top of my profession, while you preside over the kiddie table of yours.

Sheldon: I see no organizational system in here whatsoever. Which panties do you wear on Mondays?
Penny: I don't need panties, I just need shorts and a shirt.
Sheldon: My mother always told me one should wear clean underpants in case one is in an accident.
Penny: One was already in an accident.
Sheldon: Doesn't mean one won't be in another, especially if I'm driving.

Howard: How long has he been stuck?
Leonard: Hmm, intellectually about 30 hours, emotionally about 29 years.

Penny: Whatcha doin'?
Sheldon: I'm attempting to view my work as a fleeting peripheral image so as to engage the superior coliculus of my brain.
Penny: Interesting. I usually just have coffee. Have you been up all night?
Sheldon: Is it morning?
Penny: Yes.
Sheldon: Then I've been up all night.

Sheldon: Excuse me, are you saying that Wil Wheaton, a.k.a. Ensign Wesley Crusher on Star Trek: The Next Generation, is going to be participating in your tournament?
Stuart: I'm sorry, did I rob you of the opportunity to stumble onto that for yourself?
Sheldon: No, wait, you don't understand. Growing up, I idolized Wil Wheaton. You know, Wesley Crusher had an eidetic memory just like me.
Raj: Oh, what a coincidence. Maybe you can discuss that with him while you're playing in the tournament. Sign here.
Sheldon: Yeah, I was such a fan that in 1995, I traveled 10 hours by bus to a sci-fi convention in Jackson, Mississippi wearing my Starfleet Academy cadet uniform in order to meet Wil Wheaton and get him to autograph my mint-in-package Wesley Crusher action figure.
Raj: Oh, It'll be like a reunion then. Sign here.
Sheldon: (Mood changes) Yeah, my arduous journey, however, was for naught. Although advertised to appear, he did not show up. It was at that moment I vowed eternal hatred for Wil Wheaton.
Raj: Okay, great, you can tell him you hate him, sign here.
Sheldon: It might interest you to know that Wil Wheaton currently ranks 6th on my all-time enemies list, right between director Joel Schumacher, who nearly destroyed the Batman movie franchise, and Billy Sparks, who lived down the street from me and put dog poop on the handles of my bicycle.

Sheldon: That's the toilet?
Policeman: Well, it ain't a wishin' well!
Sheldon: Please tell the judge I'm ready to apologize.

Leonard: Think about what this represents. The fact that we can do this is the only way of definitively proving that there are man-made objects on the moon, put there by a member of a species that only 60 years before had just invented the airplane.
Zack: What species is that?

Raj: I like the new look.
Howard: Thanks. I call it the Clooney.
Raj: I call it the Mario and Luigi but whatever.

Sheldon: There's an economic concept known as a positional good in which an object is only valued by the possessor because it's not possessed by others. The term was coined in 1976 by economist Fred Hirsch to replace the more colloquial, but less precise "neener-neener".

Penny: What's this cartoon called again?
Leonard: Oshikuru: Demon Samurai.
Sheldon: And it's not a cartoon, it's anime.

Leonard:What am I supposed to say? Sure, Penny, I'm cool with having your old boyfriend sleep in your apartment.
Leonard imitating Penny: Well, Leonard, it doesn't matter if you're cool or not, 'cause I'm penny and I'm pretty and I can do whatever the hell I want.