Leonard: Penny and Leonard 2.0. We can test it internally, shake out the bugs, and if we both think it is solid, we roll it out to the public.

Leonard: Hey, how about if we pretend we're actually on a first date? See how that goes.
Penny: Okay.
Leonard: So, Polly, tell me about yourself.
Penny: It's Penny.
Leonard: Oh, sorry, yeah. Awkward.

Leonard: Obviously, when I saw that you were in ours, I went and used another one.
Sheldon: Where?
Leonard: The gas station across the street.
Sheldon: In your pajamas?
Leonard: Yes.
Sheldon: Without shoes?
Leonard: Yes.
Sheldon: On a cold winter's night?
Leonard: Yes.
Sheldon: Seems unlikely. Did you bring your asthma inhaler?
Leonard: Uh, uh, uh. Yes, I did!
Sheldon: Well, then, I guess it's plausible.

Sheldon: Leonard?
Leonard: Yeah, hi, hi. How's it going?
Sheldon: Uh, can't complain. Thanks for asking. What were you doing out at three o'clock in the morning?
Leonard: Well, uh - uh, what are you doing up?
Sheldon: I was using the bathroom.
Leonard: Yeah, well, so was I.
Sheldon: Really? I didn't see you in there.

Bernadette: Do you think you'll sleep with him tonight?
Penny: Absolutely not. Look, we're just gonna have dinner and, you know, see how it goes.
Amy: If he were dying, would you sleep with him?
Penny: What?
Amy: Assuming he were dying of something that couldn't be sexually transmitted. You know, like a spear wound to the head.
Penny: Okay, he is not dying.
Amy: How do you know? Are you a doctor?

Bernadette: You can make-believe, though. Sometimes Howard and I pretend that his arrhythmia is acting up and I'm a sexy cardiologist. And the naughty part is I'm not in his HMO network.

Bernadette: Relax, you know Leonard's always been crazy about you. It's gonna be great.
Penny: I know, but we've finally gotten to a place where we can hang out without it being weird. And what if something goes wrong? Then what?
Amy: Guess it'll just be Sheldon and me going on a double date with Howard and Bernadette.
Bernadette: Sure, we'd love that. (To Penny) Change your clothes, we got a lot riding on this.

Sheldon: I don't understand the laughter. The object of Settlers of Catan is to build roads and settlements. To do so requires wood. Now, I have sheep. I need wood. Who has wood for my sheep?

Sheldon: The reason you're fixated on a good-natured simpleton like Penny is that she's the exact opposite of your first romantic attachment, your brilliant yet intimidating mother.
Leonard: Where on earth did you get that from?
Sheldon: It's in her book, "Needy Baby, Greedy Baby".
Leonard: That doesn't make it true.
Sheldon: It's called non-fiction for a reason, Leonard.

Raj: If they ever make a movie version of that book, you know who should play Leonard's mother? Sandra Bullock.
Howard: Why?
Raj: Because she's great in everything.

Leonard: So, do they have a name for a first date with someone you used to go out with?
Penny: Oh, that's a good question. How about awkward?
Leonard: Yeah, that sounds right.

Penny: Okay, uh, let's see. I'm from Nebraska, and ever since I was a little girl, I dreamed of moving to L.A. and becoming a movie star. Anyway, after four years of acting lessons and waiting tables, I've done a hemorrhoid commercial and a production of Anne Frank above a bowling alley. So, you know, dreams do come true.

Leonard: Uh, let's see. Uh, I am an experimental physicist at Cal-Tech, most of my research is with high-powered lasers, and, oh, I've just gotten a big government grant to see if they can be used to knock out incoming ballistic missiles.
Penny: Wow. Can they?
Leonard: Oh, God, no. The money's pretty good. And I used the equipment to make my own Bat-signal.

Penny: You are so funny.
Leonard: Good. Remember that when I take my shirt off.

Penny: You're over-thinking this.
Leonard: No, I'm not.
Penny: Yes, you are. You always over-think things.
Leonard: Ah, now there you go. Always made it worse.