Amy: Are you in the lanthanide series?
Sheldon: Amy, it's Penny's turn. Penny.
Penny: Uh, I dunno. Are you food?
Sheldon: That's not a apropos! We've already established I'm found on the Periodic Table.
Penny: Well, it's a table, right? I mean, why can't there be food on it?
Sheldon: I knew she wasn't lead car material.

Raj: I don't like bugs, okay. They freak me out.
Sheldon: Interesting. You're afraid of insects and women. Ladybugs must render you catatonic.

Sheldon: Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and as it always has, rock crushes scissors.

Sheldon: Why are you crying?
Penny: Because I'm stupid.
Sheldon: That's no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and that makes me sad.

Howard: What, I'm not hot enough for Angelina Jolie?
Raj: Id like to weigh in here: No.

Sheldon: Good morning everyone and welcome to "Science and Society". I'm Dr. Sheldon Cooper, BS, MS, MA, PhD and ScD. OMG, right?

Sheldon: I need to sleep here tonight.
Raj: Why?
Sheldon: Howard is a total ass, Bernadette is in Penny's bed, Amy bites and Penny may or may not have coitus with Leonard.
Raj: Okay, come in.