Leonard: Oh. Oh! I just thought of the murder weapon!
Penny: Swiss army knife?
Leonard: (laughs) No. [after Penny leaves] That's way better.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Amy: So, you're just gonna sit here by yourself and do nothing?
Sheldon: Of course not. I'm going to write mean comments about Wil's show online.
Amy: Well, you can't criticize something you haven't seen.
Sheldon: I'm sorry, are you familiar with the Internet?

Sheldon: Oh, Amy. Good, you're here.
Amy: Hi. What's up?
Sheldon: How would you like to be on television?
Amy: Is it gonna be a news story where I have to say you were quiet and kept to yourself and I'm as shocked as anyone?

Wil Wheaton: [on TV] It's time for Professor Proton's science joke of the day. Why can you not trust atoms?
Sheldon: Hmm.
Wil Wheaton: [on TV] Because they make up everything.
Sheldon: Oh, that's funny! Yeah, because they do. They make up everything.