Sheldon: It reminds me of when my stupid brother and sister would build forts in the living room, and wouldn't let me in. I hated that so much.
Amy: You know, there's nothing I can do about getting you invited to the symposium, but if you wanted we could build a fort.
Sheldon: Isn't that a little juvenile?
Amy: More juvenile than this? *Puts up picture of smiling Sheldon to her face*

Sheldon: I really did think you looked pretty.
Amy: You did?
Sheldon: Yes. So much so that I started to panic.
Amy: Well you can relax. Just because you think I look pretty doesn't mean we have to spend the night together.
Sheldon: Were you hoping we would because it's prom?
Amy: I'm always hoping. But tonight, I just wanted to have a nice time with you. Maybe dance with someone who has arms.

Penny: At one point, they had me figure out how to get a banana out of a puzzle box.
Leonard: Wait, Sheldon gave me a banana in a box. He was testing me, too.
Penny: Unbelievable.
Leonard: And how could a chimp even solve that? That was impossible.
Penny: Really? You couldn't get it out?

Howard: I invented a game. Want to play?
Leonard: Sure.
Howard: It's called Emily or Cinnamon. I give you actual quotes I've heard Raj say, and you guess if he was talking to his girlfriend or his dog.

Penny: Sheldon, we know this is a sensitive subject, and Leonard's not going to move out until you're ready.
Sheldon: What if you did it gradually?
Leonard: All right, how about we start with two nights a week I live with Penny?
Sheldon: How about one night and I let you whistle?
Leonard: Okay.
Sheldon: When I'm not home.

Sheldon: Thank you for understanding.
Amy: Of course I understand. Sheldon, there's something else I've been wanting to say, but before I do, I just. I want you to know you don't have to say it back. I know you're not ready and I don't want you to say it just because social convention dictates -
Sheldon: I love you, too.
Amy: You said it.

Penny: Wait, what is wrong with you two? He was talking about television during their date night.
Sheldon: Oh, not just date night. Our 5th anniversary.
Penny: Okay, see, that's even dumber than you wondering if being bitten by a goat would give you the powers of a goat.
Sheldon: If that happens, don't make me wait ten years to watch you eat a tin can.

Howard: How are the taxes going?
Bernadette: Okay, but you've got a lot of receipts for the Lego store in here.
Howard: Those are business expenses. You can write those off.
Bernadette: A $200 R2-D2 is a business expense?
Howard: Oh, Bernie, you're gonna have to sound a lot more confident when we get audited.

Mary Cooper: When your mom gets back, I'm gonna need to apologize for the way I spoke to her.
Penny: Well, come on, she did kinda start it.
Mary Cooper: Doesn't matter. A good Christian would have turned the other cheek. On the other hand, a good Texan would have shot her, so I'll just split the difference.

Leonard: Well, you can spend the rest of the day being bitter about this--
Sheldon: Agreed.
Leonard: I was going to say "or," but why bother?

Sheldon: I'd like to take a moment to personally thank Dr. Amy Farrah Fowler, who you may or may not know is the first woman to co-host a flag or banner related Internet infotainment show.
Amy: Take that glass ceiling!

Penny: This is why I've been saying we should keep champagne on ice.
Sheldon: Sarcasm?
Amy: Yes.
Sheldon: That was tricky because when it comes to alcohol, she generally means business.

Raj: Okay, here we go.
(To Leonard & Penny) Say cheese.
(To Sheldon & Amy) Say cheese.
(To Howard & Bernadette) Say cousin.

Sheldon: I like it. I think you're on to something.
Leonard: Really? You're not messing with me?
Sheldon: Not at all. In fact, I have got something for just such an occasion. I was starting to think I'd never get a chance to give it to you. Good job!
Leonard: You're giving me a sticker?
Sheldon: Not just a sticker. That's a sticker of a kitty saying "Mee-wow".
Leonard: I'm not a preschooler.
Sheldon: Fine, I'll take it back.
Leonard: I earned this. Back off.

Raj: So, what's up with you guys?
Howard: We're just saying all the things we love about each other.
Raj: Oh, like you and I did at couple's therapy?