Leonard: She didn't dump me. We were just in different places in the relationship.
Sheldon: I fail to see how a relationship can have the qualities of a geographical location.
Wolowitz: It's very simple. Leonard was living in a little town called "Please don't leave me", while Penny had just moved to the island of "Bye-bye!"

Leonard: Relax, it's just a dirty sock.
Sheldon: How on earth can you say "dirty sock" and "relax" in the same sentence?

Sheldon: Stop it both of you! All this fighting, I might as well be back with my parents!
*Imitating his Mom* Dammit, George! I told you if you didn't quit drinking I would leave you!
*Imitating his Dad* Well, I guess that makes you a liar, because I'm drunk as hell and you are still here!
*Imitating his Mom* Stop yelling, you're making Sheldon cry!
*Imitating his Dad* I'll tell you what is making Sheldon cry, that I let you name him SHELDON!

Bernadette: Come here, tushie face.
Leonard: Tushie face! That is going on twitter right now.

Penny: You gotta help me get my arm into my sleeve.
Sheldon: (Eyes closed) Okay!
Penny: Is that my arm?
Sheldon: It doesn't feel like an arm.
Penny: Then maybe you should let it go.

Zack: Is that the laser? It's bitchin'.
Sheldon: Yes. In 1917, when Albert Einstein established the theoretic foundation for the laser in his paper "Zur Quantentheorie der Strahlung", his fondest hope was that the resultant device be bitchin'.
Zack: Well, mission accomplished!

Sheldon: You know, I've always wanted to go to a goth nightclub.
Howard: Really?
Sheldon: Bazinga! You never see any of my practical jokes coming, do you?

Sheldon: It was you. I touched you!
Penny: Happy Valentine's Day.

Howard: What's the matter, you chicken?
Sheldon: I've always found that an inappropriate slur. Chickens are not by nature at all timid. In fact, when I was young, my neighbor's chicken got loose and chased me up the big elm tree in front of our house.
Raj: Chickens can't climb trees.
Sheldon: Thank God.
Howard: Okay, I believe the chicken made you his bitch.

*Sheldon is using a map of the U.S. to find out where he can move*
Sheldon: Penny, you're from Nebraska, right?
Penny: Born and raised.
*Sheldon crosses out Nebraska*

Sheldon: Good Morning your honor, Dr. Sheldon Cooper appearing in pro se - that is to say representing himself.
Judge: I know what it means, I went to law school.
Sheldon: Yet you wound up in traffic court.

Sheldon: Howard, you know me to be a very smart man. Don't you think that if I were wrong, I'd know it?

Mrs. Wolowitz Howard, are you having a playdate?
Howard: I don't have playdates. I have colleagues.
Mrs. Wolowitz Do their parents know they're here?
Howard: No, but if you keep screaming, maybe they'll hear you.

Raj: Hey, Leonard?
Leonard: Yeah?
Raj: I haven't had sex in a year.
Leonard: Where are you going with this, Raj?
Raj: Don't flatter yourself, dude.

Howard: 1. I lost my virginity to my cousin, Jeanie. 2. It was my Uncle Murray's funeral, we were all back at my Aunt Barbara's house. Our eyes locked over the pickled herring. We never meant for it to happen. 3. To this day, I can't look at pickled herring without being aroused and ashamed. Oh, cousin Jeanie.