Sheldon: Well, if you are so protective of the scientific method, perhaps we should use the next five weeks to finish what we started.
Amy: Well, for science, maybe I will!
Sheldon: For science, maybe you should!
Amy: Fine!
Sheldon: Fine!
Amy: Good.
Sheldon: Great.
Amy: Do you want to go to our place and make out?
Sheldon: Does Stephen Hawking roll through the quad?

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.

Penny: We wouldn't even sit in your spot while you're gone.
Sheldon: You're darn right, you wouldn't. No matter where I am, this will always be my spot. Like an embassy in a foreign country, this seat is the sovereign soil of my bottom.

Penny: The new neighbors are weird.

Penny: Do they know why the pipes burst?
Amy: They didn't say.
Leonard: Buildings that have a combination of copper and galvanized steel are susceptible to pinholes and corrosion caused by the mobility of ions in the water. Can't have your head shoved in a toilet as much as I did and not pick up a few things about plumbing.