Beverly Hofstadter: His name is Sigmund Freud.
Penny: Hey! Look at that. You both believe in Jewish bearded guys.
Mary Cooper: Stay out of this.
Penny: Uh-huh.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Raj: [to Amy] If you were having Sheldon's baby, would you really want him in the room?
Penny: Yeah, if he's in the room when they're making the baby, I'll give you $10.

Penny: I mean, who even reads Scientific American?
Leonard: It's kind of a big deal.
Penny: If it's such a big deal, how come the biggest celebrity they could get for the cover is a molecule?

Mary Cooper: When your mom gets back, I'm gonna need to apologize for the way I spoke to her.
Penny: Well, come on, she did kinda start it.
Mary Cooper: Doesn't matter. A good Christian would have turned the other cheek. On the other hand, a good Texan would have shot her, so I'll just split the difference.

Leonard: Not once did my mother ever give me any love or affection for just being myself. I always had to earn it.
Mary Cooper: Oh, Leonard, I'm sure she loves you very much. In her own cold godless way.

Mary Cooper: Well, I would have to say when he was thirteen and he tried to build a nuclear reaction in the tool shed.
Sheldon: Ooh, this is a good one.
Mary Cooper: Now, the first thing you need to know about Shelly is, ever since he was a little boy, he was always concerned with the well-being of others. And he didn't think it was fair for people to pay for electricity, so he was gonna power the entire town for free.
Sheldon: Tell her about the uranium. Tell her about the uranium!
Mary Cooper: Oh, well! Well, this is adorable. When he arranged to get some yellow-cake from Chad, I thought he was talking about twinkies from one of his friends.
Sheldon: Yeah. But I wasn't, because I didn't have any friends.
Mary Cooper: No. It turns out this little scallywag was trying to use my Visa card to buy uranium from an African warlord in the country of Chad.