Mary Cooper: Now, the reason I called Amy over was to find out what kind of person she is. Now, after chatting a bit, I have to say that while she is a perfectly ... unique ... young woman, you two are definitely not suited for each other.

Mary Cooper: Well, putting aside the pig Latin. It's a good a thing you two decided to end the relationship so I didn't have to end it for you.

Leonard: I saw what you did there.
Mary Cooper: He thinks he's such a smarty pants. He's no different from any man. You tell him not to do something, that's all they want to do. If I hadn't told my brother Stumpy not to clear out the woodchipper by hand, we'd still be calling him Edward.

Mary Cooper: Now, don't you move. I'll bring over all the food.
Leonard: No, I can do it.
Mary Cooper: Well, isn't that sweet.

Raj: Penny, dear, why don't you shoot another silver bullet my way?
Penny: Get one yourself.
Raj: Ooh, somebody's been taking bitchy pills.
Penny: God, he's an ass when he drinks.
Howard: Oh, he's an ass when he doesn't. You just don't hear it.

Sheldon: I brought Amy here to show her some of the work I'm doing.
Amy: It's very impressive, for theoretical work.
Sheldon: Do I detect a hint of condescension?
Amy: I'm sorry, was I being too subtle? I meant compared to the real-world applications of neurobiology, theoretical physics is - what's the word I'm looking for? Hmm, cute.
Sheldon: Are you suggesting the work of a neurobiologist like Babinski could ever rise to the significance of a physicist like Clerk Maxwell or Dirac?
Amy: I'm stating it outright. Babinski eats Dirac for breakfast and defecates Clerk Maxwell.

Leonard: What's a dogapus?
Sheldon: A hybrid dog and octopus. Man's underwater best friend.
Leonard: There's someone working on that?
Sheldon: I was going to. I planned on giving it to myself for my 300th birthday.
Leonard: Wait a minute you hate dogs.
Sheldon: A dogapus can play fetch with eight balls; no one can hate that.

Howard: Hey look, it's Leonard and R2-D-bag!

Raj: I'm a lamb!

Leonard: Penny, Steve Wozniak was one of the co-founders of Apple computer. He and Steve Jobs.
Penny: Yeah. I know who he is. I watch Dancing With the Stars.

Penny: Hey. Nice knees.
Sheldon: Thank you! They're my mother's.

Penny: What up, Shel-bot?

Leonard: What ya doin' there? Working on a new plan to catch the Road Runner?

Sheldon: What I am doing here is trying to determine when I am going to die.
Leonard: A lot of people are working on that research.

Sheldon: At my age, do you know how I'm statistically most likely to die?
Leonard: At the hands of your room mate?
Sheldon: An accident.
Leonard: That's how I'm going to make it look.