Sheldon: The answer is cuddly soldiers with big flat noses. Moving on.

Penny: You couldn't sleep either?
Leonard: Of course not.
Sheldon: Me neither. But I just had a tickle in my throat. Not profound marital problems.

Bernadette: You know who would be the perfect roommate?
Sheldon: Gandalf, but he's a smoker.

Leonard: Mr. Nye, hello. I'm sorry he got you involved in this nonsense.
Bill Nye: He told me I'd be speaking to a class.
Sheldon: No, I said you were teaching someone a lesson.

Sheldon: *knock knock knock* Penny! (x3)
Penny: Sheldon, what is it?
Sheldon: Leonard's asleep.
Penny: Thanks for the update.

Sheldon: My mother would lock her car if she had to drive through his hodgepodge of ethnicity.

Penny: I don't understand why you're not upset with Amy.
Sheldon: I am. So much so that I'm going to bring her here for dinner on our next date night.

Sheldon: I miss Stuart's place. All this loud music and exposed brick, is this a comic book store or a rave at the third little pig's house?

Sheldon: I just want you to get better as soon as possible. And with that in mind, let me ask you a question. Do you believe in the placebo effect?
Amy: Of course I do. There have been many studies proving its validity.
Sheldon: Great. Now, this may look like a Tic Tac, but it is really a powerful medication specifically designed to cure your illness as well as freshen your breath.

Sheldon: Look, I am simply going to defend our work, scientist to scientist. And, failing that, suggest that his mother enjoys a string of both human and non-human lovers.

Penny: Isn't tomorrow your usual laundry night?
Sheldon: The supermarket was out of my regular fabric softener. If this one under or over-softens, I'll need time to make things right.
Penny: That's thinking ahead.
Sheldon: The alternative would be to think backwards. And that's just remembering.

Sheldon: Payback, it truly is the B word, isn't it?

Howard: Step one, rapidly flip the calibration switch from the fully up to the fully down positions for at least ten times.
Sheldon: It actually says "at least"?
Howard: Yeah.
Sheldon: Why would they say "at least"? Is it 10 toggles? Is it 100 toggles? Is it 1,000 toggles? 10,000 toggles? 100,000 toggles?
Howard: Sheldon!
Sheldon: You see where I'm going with this.

Raj: What's wrong with Mexico?
Sheldon: Uh, Mariachi bands, wild dogs, beans that jump around because there's a worm inside.

Sheldon: Are we all up to date on our yellow fever inoculations?
Howard: You don't need a yellow fever shot to go to Mexico.
Sheldon: You can never be too careful. I got one last year before I went to Epcot.