Leonard: You feel like trying something new for dinner? Maybe Indian, Tex-Mex?
Sheldon: You ever wonder how humans would be different if they evolved from lizards instead of mammals?
Leonard: Okay, let's talk about that.
Sheldon: As you know, lizards, cold-blooded animals, lack the ability to sense temperature. But they do move more sluggishly when it's cold. So, lizard weathermen would say things like, bring a sweater, it's slow outside. I love my mind.
Leonard: We all do. Now, how about dinner?
Sheldon: Oh, I would assume we'd enjoy insects or smaller lizards. We could also pull each other's tails off and grill them, they'll just grow back.

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.

Bernadette: Boy, I don't know if I could be friends with Howie if we broke up.
Howard: Why not?
Bernadette: I'm a very vengeful person.
Howard: Really?
Bernadette: With access to weaponized smallpox.

Sheldon: Does anybody have any wood? Oh, come on! I just want wood. Why are you making it so hard?

Sheldon: I know he (Spock) wouldn't care for an outburst of human emotion, but oh goodie, oh goodie, oh goodie!