Leonard: If I roll down the windows, everything is peachy. If you roll down the windows, you're still not a doctor.

Zack: (At Penny's door) Babe, open up.
Penny: I'm not talking to you.
Zack: Then who are you talking to? Babe?

Sheldon: I sense that you're trying to slow walk me to an epiphany. Would you mind very much jumping to it.

Sheldon: So, this conversation is as pointless as your door knocking soliloquy?
Penny: Let me get my cockamamie keys.

Sheldon: According to the Roommate Agreement, Paragraph 9, Subsection B: The right to bathroom privacy is suspended in the event of force majeure, and believe me, I am experiencing a very majeure force.

Sheldon: When he finished, he shouted "Eureka"!
Zack: No, I always shouted, "Holy, moly!" Don't know why, just do.

Sheldon: It's not a touch phobia, it's a germ phobia. If you'd like to put on a pair of latex gloves I'll let you check me for a hernia.

Sheldon: Leonard, social protocol states when a friend is upset, you offer them a hot beverage, such as tea.
Howard: Tea does sound nice.
Sheldon: You heard the man, Leonard. While you're at it I am upset we have an unannounced house guest, so make me cocoa.

Leonard: Nice to know everything's OK with your plumbing. Err, the building's plumbing.

Sheldon: At one point Raj put on reggae music and his sister took off her shoes. It was like the last days of Caligula.

Sheldon: Will you Boozehounds stop that infernal clinking? And the Answer was Elephant.

Leonard: Open the landing bay doors, shuttle craft approaching.

Leonard: What do you mean it happened again?!

Sheldon: Howard, the person at fault for you not getting a security clearance is me.
Howard: You?
Sheldon: Yes, but before you get upset, I want you to know I went to the FBI and retracted my statement.
Howard: And they were okay with that?
Sheldon: No. If anything, I made it worse.

Penny: That's amazing.
Sheldon: I wouldn't say amazing. At best it's a modest leap forward from the basic technology that gave us Country Bear Jamboree.
Howard: Hey, Sheldon? Ahem.
Sheldon: Yes?
*Howard commands the robot arm to perform a hand gesture*
Sheldon: Peace?
Howard: No, not peace. Hang on.