Penny: What do you mean new roommate? What happened to Leonard?
Sheldon: The same thing that happened to Homo Erectus. He was replaced by a superior species.
Raj: I'm the new homo in town.

Penny: So that means, you're a doctor, you're a doctor, you're a doctor, you're a doctor and, Howard, you know a lot of doctors.

Sheldon: Here's an interesting fact about alcohol: Man is not the only species that ferments fruit in order to become intoxicated. Can you guess what the other is? Hint: sometimes they pack the alcohol in their trunks.
Penny: Monkeys.
Sheldon: When does a monkey have a trunk?
Penny: When a suitcase just won't do.

Raj: Can I bring girls here?
Leonard: You? Sure. Bring as many as you want.
Raj: Okay, deal.
Leonard: Just not against their will.

Penny: Hey, Sheldon, did you change your Wi-Fi password again?
Sheldon: Yes, it's "Penny get your own Wi-Fi"; no spaces.

Penny: Really still can't talk to me?

Leonard: What's going on?
Penny: Oh, hey, it's not what it looks like. *Leaving*
Sheldon: What does it look like?

Sheldon: What are you doing here?
Leonard: I live here.
Sheldon: I have paperwork that says differently.

Howard: You gotta like this: the girlfriend, the ex-girlfriend, bonding over your rooty-tooty stinky booty? (All but Leonard laugh)
Leonard: Kill me.
Sheldon: It wouldn't help. The human body is capable of being flatulent for hours after death.

Sheldon: What are you doing here?
Howard: I've been up all night. I had a fight with Bernadette.
Sheldon: Why?
Howard: She bought me a nice watch.
Sheldon: Leonard, do you understand any of this?
Leonard: Yes.
Sheldon: Talk to him.

Raj: Come on, dude, I'm exhausted and Tyra Banks says the most important item in your makeup bag is a good night's sleep.

Sheldon: Oh Amy, I've never been touched like this before.

Amy: I was proposing massaging your muscles with your own hands.
Sheldon: Still sounds like a lot of unnecessary touching.

Raj: Well, uh, to paraphrase Shakespeare, "It's better to have loved and lost than to stay home every night and download increasingly shameful pornography."

Sheldon: I never joke about safety.