Don't be insulted. He just thinks too much of you would be mind-numbingly tedious.

Hello, Penny. I realize that you're currently at the mercy of your primitive biological urges, but as you have an entire lifetime of poor decisions ahead of you, may I interrupt this one

I've been informed that he's now Bill Nye the Restraining Order Guy.

Alright, so the topic at hand is sexual fidelity. Probably won't be relying on Seuss here. Although 'One Fish, Two Fish, Red Fish, Blue Fish' might be surprisingly applicable.

Sheldon: Are you asking me or telling me?
Leonard: Telling you?

I think your morning Cocoa Pops are turning you into a hysterical woman.

Leonard: If we do get a new friend, he should be a guy you can trust. You know, a guy who has your back.
Wolowitz: And he should have a lot of money and live in a cool place down by the beach where we could throw parties.
Sheldon: And he should share our love of technology.
Wolowitz: And he should know a lot of women.
Leonard: Okay, let's see: money, women, technology. Okay, we're agreed. Our new friend is going to be Iron Man

Sheldon: Things between you and Penny have never been better. I hope 4 months apart doesn't change anything.
Leonard stops car.
Sheldon: I should have opened with that, huh?

Sheldon: The entire nation dedicated a decade of effort and treasure to put a man on the moon.
Wolowitz: Well, my fellow Americans, before this year is out we will put a Wolowitz on one of America's top models.
Raj: And a large number of people will believe it never happened

Sheldon: Wow. This is truly remarkable.
Alex: Thank you.
Sheldon: I think I'll keep it for myself.
Alex: What about your girlfriend?
Sheldon: It's too late, I call dibbs.

Amy: Sheldon, you're not a weirdo.
Sheldon: I wasn't speaking about me.

Leonard: We think we can help you with your stage fright.
Sheldon: Oh, I doubt that. I haven't figured out a way, and I'm much smarter than all of you.
Penny: Yes, buy you're not smaller than all of us put together.
Sheldon: I'm sorry, that is what I meant.

TBBT Quotes

Oh, Bernadette, please play my clarinet.

Raj's poem

Sheldon: I'll have a diet Coke.
Penny: Can you please order a cocktail? I need to practice mixing drinks.
Sheldon: Fine... I'll have a virgin Cuba Libre.
Penny: That's... rum and Coke without the rum.
Sheldon: Yes, and would you make it diet?