Leonard: I got you something for Valentine's Day and I was too embarrassed to give it to you.
Penny: Why?
Leonard: Because I got it at the dirty store.
Penny: You went to the dirty store without me?
Leonard: In sun glasses and a hat after I parked two blocks away.

Penny: Did we move at all?
Leonard: Maybe a long the Z axis, but X & Y are looking pretty sad.

Penny: Now come on, we are gonna do this.
Leonard: Yeah. You get the paint, I'll rest for thirty to forty minutes, and then we do this.

Leonard: Please go to Mars.

Amy: I just read about an experiment designed to see if you can make two people fall in love in a matter of hours.
Leonard: That doesn't sound right. My research has shown it takes three to five years of shameless begging.
Penny: Honey, neither of us comes off good in that story.

Leonard: Ladies,
Emily: Are you being polite or scared?
Leonard: Yep.

Leonard: The place really looks great.
Raj: Yeah, you should have burnt it down years ago.
Stuart: I keep telling you, I didn't burn it down.
Leonard: We know. We know. Because burning something down for the insurance money is a crime. *wink*

Leonard: Why don't we go get the food for the party?
Stuart: Thank you.
Raj: Smart. Looks like we're being helpful.
Leonard: When really we're just exiting an uncomfortable situation. *fist bumps with Raj*

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

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.

Leonard: One calls it insightful and innovative. We're insightful and innovative.
Sheldon: Nice to meet you, Mr. Insightful.
Leonard: Ah, the pleasure is mine, Mr. Innovative.

Leonard: "Upon review, I've changed my mind about the Cooper-Hofstadter hypothesis that space-time is like a super-fluid. In fact, it's inspired me to come up with my own theory. Maybe space-time is like two clowns with their heads in a bucket. Much like Cooper and Hofstadter."

Leonard: Do you really want him to write back?
Sheldon: I do. And no matter how he responds, I'm going to destroy him with a picture of a bored cat saying "Oh, really?"
Leonard: Mee-wow.

Raj: I'm sick of people being mean on the Internet.
Howard: I think the anonymity makes everyone feel like they can say things they'd never say to your face.
Sheldon: Interesting. I can't think of a single thing I wouldn't say to someone's face.
Leonard: Never noticed that about you.

Leonard: Your George Lucas autograph is really a me autograph.