Penny: What got you excited about dark matter in the first place?
Sheldon: Well, I left string theory, which I'd been working on for a long time, and everyone was talking about how cool dark matter was, and I thought, "€œWell, sure, I'll give that a whirl".
Penny: So it's your rebound science?
Sheldon: What's that?
Penny: Well, not the science you spend the rest of your life with, but the one you use to make yourself feel pretty again.

Leonard: If I take it off, Sheldon wins.
Penny: Sweetie, every night you don't kill him in his sleep, he wins.

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?

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

Howard: (singing) Alone in my temple in the middle of Peru, A giant stone ball with nothing to do,
Raj: But if you steal my idol, I will roll right over you
All: Cause I'm six tons of granite, And micaceous schist. Yeah, I'm six tons of granite, And micaceous schist,
Bert: I'm gonna crush you, I'm gonna mush you, You took my idol, I'm homicidal, Gonna roll over you till your brains come out, And your bones will crunch and your blood will spout! I'm not just a rock, baby. I'm a boulder.
All: Cause I'm six tons of granite, And micaceous schist. Yeah, I'm six tons of granite, And micaceous schist, Yeah, I'm six tons of granite-

Howard: What up, my Hebrews and She-brews?!

Mary Cooper: Oh, Shelly. I have bad news. Mr. Watkins passed this morning.
Sheldon: Oh. Oh, I'm-I'm sorry.
Mary Cooper: I know. What are the odds of that?
Sheldon: Call you back.