Amy: Well, for starters, there's nothing wrong with keeping our toothbrushes in the same holder.
Penny: Sheldon, what do you say to that?
Sheldon: I think we should see other people.

Sheldon: Hello?
Leonard: Oh, hey, where you been? We've been calling you for hours.
Sheldon: Oh, I'm sorry, my phone was on "airplane" mode.
Leonard: Why?
Sheldon: Because I was on an airplane. (makes confused gesture to Amy)

Sheldon: First, talking to you while you're on the toilet isn't exactly a picnic for me either. Remember, when you can hear me, I can hear you.

Adam Nimoy: What was it about Spock that appealed to you?
Sheldon: I think the same thing that appeals to people everywhere, the dream of a cold, rational world entirely without human emotion.
Spock came from a planet governed only by logic.
You know, on Vulcan, when your brother asks, "Why are you hitting yourself?" The answer is, "I'm not. You're moving my arm." To which he says, "fascinating." And then you both watch educational television.

Leonard: When did we get a wall safe?
Sheldon: When there was no more room in the floor safe.
Leonard: When did we get a floor safe?
Sheldon: When we got the security camera.
Leonard: There's a security camera?
Sheldon: Aquaman, protecting your home since 2012.
Penny: Oh, my God. We've done things on that couch.
Sheldon: Yeah, you don't have to tell me.

(Leonard standing outside the door to Sheldon and Amy's apartment)
Leonard: Help! Cinnamon's loose in the building!
Sheldon: (Inside) Amy, quick, lock the door!

Penny: I thought you were looking at a cliff on the beach.
Amy: We were, but Sheldon didn't like any of them. Some were too beachy, some were too cliffy.
Sheldon: And all of them were too outsidey.

Sheldon: I suppose I could see myself in a scientific boyband. Of course I'd be the dreamy one and the smart one.

Raj: And you know we get to name it.
Sheldon: We better choose a name no one can make fun of. Sir Frederick William Herschel didn't do Uranus any favors.

Sheldon: Read it back to me?
Leonard: Oh, hang on. "Yes, one might question the $20 billion "to build and run the Large Hadron Collider, but on the other hand..."
Sheldon: Okay. Um, oh, oh! "On the other hand, contrary to predictions, the collider didn't create a small black hole that devoured the Earth and life as we know it." So, money well spent.

Leonard: I'm a little nervous.
Sheldon: Well, get over it. Confidence is key in these situations.
Leonard: Right. *Pushes button*
Sheldon: You pushed it! Are you out of your mind?

Sheldon: Who would win in a fight, you or a shark?

Sheldon: But I need it. It's the only way to settle the contradictions between gravity and quantum mechanics.
Penny: Well, it's too much money, you can't ask for that all at once.
Sheldon: Well, what if I ask for it in six easy installments of $83,333,333.33?

Leonard: Hey, I made French toast sticks.
Sheldon: On oatmeal day?
Leonard: Ah, I also made oatmeal.
Sheldon: Ooh, that's a lot of carbohydrates for a man on the prowl. You know what? You eat it. You're married, it doesn't matter what you look like.

Sheldon: Ladies.
Penny: What's up?
Sheldon: As you may know, I have been experimenting with elevated anxiety levels, and I thought what better way to increase my discomfort than to subject myself to an evening of tasteless, uncensored crotch talk.