Sheldon: So, did you defile my mother or not?

Penny: That's so funny. I never would have pegged you for a Pisces.
Sheldon: You're making it difficult to love you right now.

Penny: I thought they fired you guys.
Sheldon: They did, but then they hired me back.
Leonard: Well, you better not be working on our project, because we're a team.
Sheldon: Leonard, there is no "I" in team. However, there is an "I" in "I'm working with the military and you're not." There's five of them, in fact.

Amy: Why do you keep tying and untying that bow tie?
Sheldon: I can't seem to get it even.
Amy: Well, I don't think it's supposed to be even. Sometimes a little asymmetry looks good. In the Renaissance, they called it "sprezzatura."
Sheldon: The Renaissance? Amy, you know I'm more of an Enlightenment person. At some point, we have to decide how we want to raise the children.

Sheldon: "Sheldon's Mine Simulation Log, entry 4: My KitKat has melted. All is lost."

Howard: You're either on Team Leonard or Team Penny.
Sheldon: Which one picks last?
Howard: What?
Sheldon: Well, usually I'm on the team that picks last. Unless there's a kid in the wheelchair.

Sheldon: Well, I found the perfect wedding date.
Amy: That's terrific!
Sheldon: No, it's not. It was May 19, 1996. We would have had a lovely wedding. And our honeymoon would have coincided with the first appearance of the Hale-Bopp comet.
Amy: Sheldon, you were 16.
Sheldon: And in Texas. No one would have batted an eye. Oh, wait, it's no good. That's the day that Jon Pertwee, the third Doctor Who, died.
Amy: And it's in the past.
Sheldon: Hey-hey, I said it's no good. Just let it go.

Sheldon: I don't know about you but I'm very uncomfortable about this.
Amy: Why?
Sheldon: I've never seen this show before, and now I'm starting with episode 246. It's unnatural.
Amy: Just think of the first 245 as the prequel.
Sheldon: All right.

Penny: Do you even like the Beach Boys?
Sheldon: They have "beach" right in the name. What do you think?

Amy: I thought we agreed on June 15.
Sheldon: That's the day after Flag Day. Everyone'll be partied out.

Sheldon: Amy's upset? Is it about me?
Leonard: No, I think it's because we're eloping.
Sheldon: Your marriage is causing her pain? You know great, I take it back. Go ahead and do it. Yay for love!

Sheldon: Stephen Hawking is a genius. If he said 'no,' I wasn't going to waste time on her father.

Howard: All I know is he's got my mother buying four ply toilet paper. Four ply! If his butt is so delicate, why doesn't he use an Angora rabbit?
Sheldon: For starters, they shed and bite.

Sheldon: First, talking to you while you're on the toilet isn't exactly a picnic for me either. Remember, when you can hear me, I can hear you.

Leonard: You guys, what are we doing? We sent the girls away so we could focus.
Sheldon: I don't think it worked.