Sheldon: Hello, Bernadette.
Bernadette: Wait, did you just walk into my house?
Sheldon: No, Howard let me in.
Bernadette: Where is he?
Sheldon: Oh, he got in his car and drove away.

Amy: Let me guess. This thing with Tam escalated, and now you're mad at Leonard and looking for a new best friend?
Sheldon: You know me so well. It's too bad you can't be my best friend.
Amy: I can be.
Sheldon: You can't be my wife and my best friend. Who would I complain about you to?

Sheldon: I don't understand. If it's unreasonable, why should we do it?
Howard: Okay, how about this? You know in Star Wars when R2 and Chewbacca were playing holochess?
Amy: Really? Star Wars?
Sheldon: Amy, let the man speak.

Amy: Just tell me what happened.
Sheldon: Leonard talked to Tam behind my back and took his side. And after what he did to me. Can you believe it?
Amy: No. I'm-I'm shocked and outraged. Now, tell me why I'm shocked and outraged.

Sheldon: When I got accepted to grad school at Caltech, I was afraid to move so far away from home. So Tam said he'd move out here with me and be my roommate. Then, over the summer, he got a girlfriend, even after reading all the pamphlets I gave him about social diseases.
Amy: Aw, I remember when you gave me those pamphlets.

Sheldon: Anyway, Tam stayed with her in Texas, and I had to move out here all by myself.
Amy: That must've been scary.
Sheldon: It was. I was lonely, and I thought I'd never make a friend again. And for a long time, I didn't.
Amy: But then you did. And great friends. If you think about it, if Tam had moved out here with you, who knows what your life would've been like.
[Montage of classic The Big Bang Theory moments with Tam as Sheldon's roomate]

Sheldon: I think Howard hurting my feelings has in some ways made me a better person.
Amy: Hmm. Look at you, improving on perfection. How so?
Sheldon: As you were eating that Danish, I wanted to point out that the Danish isn't Danish at all. It was imported by Austrian bakers during a labor dispute in the 1800s. But I chose not to, because I didn't want to be the kind of fella who foists unwanted facts about European pastries on the unwilling.
Amy: Huh. That's actually interesting.
Sheldon: Sorry. Now you'll never know.

Sheldon: So, your convention is in San Diego, right?
Penny: Yes.
Sheldon: Great. I need you to settle a bet for Amy and me.
Amy: I say, when it's not Comic-Con, no one will be dressed as superheroes.
Sheldon: Mm-hmm. And I say fewer people will be dressed as superheroes but still some.
Amy: A crazy person in a cape doesn't count.
Leonard: Mm, why not? It counts at Comic-Con.

Anu: Come on.
Penny: There's really nothing to tell. Raj is so much fun to hang out with. He's like one of our girlfriends. And I mean that in a good way.
Bernadette: But also a bad way.

Penny: Well, people came, they ate, they vowed to never speak to each other again. I think it was a successful party.

Sheldon: Leonard, when are you leaving to pick your mother up from the airport?
Leonard: Uh, well, let's see, her plane gets in at 3:00, figure half hour to get her luggage, so never.

Penny: Never? Isn't that usually when you go to the gym?

Anu: Anything else?
Penny: No.
Bernadette: No.
Penny: I mean, he takes baths with his dog, but not in a weird way.
Bernadette: Or a normal way; they both wear swimsuits.

William Shatner: Hello.
Sheldon: Captain on the bridge! Captain on the bridge! You're William Shatner.
William Shatner: You can call me Bill.
Sheldon: Ooh, can I call you Captain?
William Shatner: No.
Sheldon: Please?
William Shatner: No.
Sheldon: [whispers] Please?
William Shatner: Sure.
Sheldon: And w-will you call me Science Officer Cooper?
William Shatner: This has got to stop.
Sheldon: I think you know how to make it stop.
William Shatner: Put her there, Science Officer Cooper.

Sheldon: Six times ten to the eighth atoms, Of a radium in a lead jar, Six times ten to the eighth atoms of radium, If the half-life of radium should happen to pass, Three times ten to the eighth atoms, Of a radium in a lead jar.
Penny: Really hope you're almost to zero.
Sheldon: No, see, that's the beauty of half-lives: it's impossible to determine when you'll arrive at zero. It's like "Wheels on the Bus" if the bus had an unknowable number of parts.