Sheldon: May I say something?
Leonard: Not right now, Sheldon.
Sheldon: But I think it may be comforting.
Leonard: Buddy-
Howard: No, it's okay. What?
Sheldon: When I lost my own father, I didn't have any friends to help me through it. You do.

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?

Leonard: What am I supposed to do?
Penny: Err, keep your mouth off other women.

Amy: But enough about Penny, let's talk about us. We're looking good.
Bernadette: We are.
Amy: Better than good. I mean look at you, your body's bangin'.
Bernadette: Amy!
Amy: Don't Amy me. We're always talking about how hot Penny is. Come on, scientist to scientist, how big are those hadron colliders?

Penny: Do you want to stop? I know you have trouble with eye contact.
Sheldon: Well, you have a brown fleck in your right iris that looks like a Formula 1 race car, so I'm just concentrating on that. Plus it's easier around people I'm comfortable with.
Penny: Oh, sweetie, I'm comfortable around you, too.
Sheldon: Of course you are. I'm warm and soothing. I'm like a human bowl of tomato soup.

Josh: So, I have to ask, was the robot sexy?
Howard: It was actually just a mechanical hand.
Josh: 'Cause that's all you need, right?
Howard: You are my brother.

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.

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*

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.

Bernadette: She's just being nice.
Howard: Well, I'm her son, how come she doesn't send someone to check on me if I'm lonely.
Bernadette: Because you have a wife!
Howard: Yeah, well, sometimes you work late.

Sheldon: There's no denying that I have feelings for you that can't be explained in any other way. I briefly considered that I had a brain parasite, but that seems even more far-fetched. The only conclusion was love.

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.

Stuart: Oh, so she's good enough for Howard but not for me?
Howard: Yeah.
Bernadette: Yeah. Go have weird relationships with your own mother and cousin. This is his turf.

Bernadette: You better find my husband's mother, 'cause one way or another we're walking out of this airport with a dead woman.

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.