Leonard: She took my Where's Waldo.
Sheldon: Well, no, no, he's over there.
Leonard: Oh, yeah, there he is.

Howard: I'm serious, JPL's actually developing a robot arm that could grab an asteroid before it hits us.
Leonard: So their plan for saving the Earth from Armageddon is hoping a bunch of scientists can catch a ball?

Leonard: You're awful quiet, everything okay?
Sheldon: I'm concerned about Amy. She's acting a bit odd lately.
Howard: Oh, well, j-just out of curiosity, what registers as odd to you?

Leonard: Damn. I burped so hard, I died in my game.

Amy: I'll miss you.
Sheldon: I'll miss you, too.
Amy: I'll miss you more.
Sheldon: Well, if X equals the amount that you'll miss me, then I'll miss you X plus one.
Amy: (giggles) If you miss me X plus one, I'll miss you open parentheses X plus one, close parentheses to the second-

Amy: Hey, there's another dance club nearby. I mean, I don't know how you feel about Latin music, but according to their "horas of operacion", they're open.
Penny: Maybe we should just call it a night.
Amy: You sure? They're open till dos.

Amy: Sheldon, it's humiliating. Thanks to you, my colleagues are gossiping about our sex life.
Sheldon: What is there to gossip about? We barely have one.

Leonard: Don't worry, we won't be doing much sleeping anyway. It's like an all-night party. There's trivia contests and Dungeons & Dragons. As we like to say, it's "off the chain mail."

Bernadette: Nobody needs a mooch living in their house forever.
Stuart: Hey, that's no way to talk about your baby.

Penny: So, relax. We're happy to have you.
Raj: Thank you, but how do I know you're not saying that just to be nice?
Penny: Do you actually pay for that haircut?
Raj: That'll do it.

Sheldon: Beverly pointed out that I'm experiencing insecurities in my relationship with Amy, in the same way that Leonard and Penny are in their relationship.
Penny: What are you talking about? We're fine.
Sheldon: Yes, you're fine as long as you have a buffer living with you to distract from your marital problems. It used to be me. Now it's Raj and his attack Tribble.

Sheldon: Well, what do you know? Here I was, waiting to be bored with biology, and instead you tickle my intellectual fancy. Which, unlike my body, is an okay place to tickle.

Leonard: Hey, Olsen twins!
Penny: What?
Leonard: Well, I mean, I'm sitting right here. You're talking about my feelings and somehow leaving me out of the conversation.

Bernadette: Plus, I think I'm setting a good example for Halley, to show her that women can be mothers and still have satisfying careers. Sure, she won't know where I went or if I'm ever coming back. That'll just make the ten minutes between when I get home (voice breaking) and her bedtime even more special.

Bert: Everyone, this is Rebecca.
Rebecca: Hi.
Everybody: Hey.
Sheldon: She's younger and far more attractive than he is. They're copying you two!