Penny: Raj, would you ever try an experiment like that with Emily?
Raj: I don't need science to win her heart, I have my family's wealth for that.

Sheldon: We're scientists, we can conduct our own research. I propose that we imprison two street people-
Amy: No.
Sheldon: You didn't even let me finish.
Amy: Forget it.
Sheldon: Oh, so you can experiment on all the apes you want, but I want to manipulate the emotions of two captive human beings, suddenly I'm the monster.

Penny: You're okay with an experiment where you have to answer awkward questions about your innermost feelings?
Sheldon: Yes.
Penny: Please can I do it with him, please.

Penny: Whenever I'd see her, she'd say I was too skinny and would try and feed me.
Amy: She did that to me, too.
Penny: Don't take this away from me.

Sheldon: I didn't care for her yelling, but now that I'm not going to hear it again, I'm sad.
Leonard: If you want, I can yell at you later.
Sheldon: It won't be as good.

Leonard: To Mrs. Wolowitz. A loving mother. To all of us. We'll miss you.

Bernadette: You helped him?
Raj: No, Stuart picked out those throw pillows all on his own.

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: I really thought he was going to say "let it go".

Stuart: I can't believe she's gone. That woman took me in. If it wasn't for her, I would have been homeless.
Amy: One of us would have taken you in.
Stuart: Yeah, I don't recall any offers. But you know what, I'm glad it worked out the way it did, because I got to know this wonderful person.

Raj: Yeah, Mrs. Wolowitz was pretty special. When I first moved to America, Howard was my only friend, and she made me feel so welcome in her home. Which says a lot, because those first few years she thought I was the gardener.

Penny: I don't want five dollars, I want my dignity.
Amy: So, what are we talking, like ten bucks?

Raj: Hang on. If you're really Nathan Fillion, what's the line from Firefly about your bonnet?
Customer: I swear by my pretty floral bonnet, I will end you.
Leonard: That's it. That's the line.
Raj: Although, I knew the line, doesn't make me Nathan Fillion.

Customer: Do you want the picture or not?
Raj: I want a picture with Nathan Fillion.
Customer: How about a picture with a guy who looks like Nathan Fillion, but a little more annoyed than Nathan Fillion usually is?
Leonard: What do you think?
Raj: Eh, it's good enough for Facebook.

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?