Leonard, why do you always do this? Listen to me, you are the one that I'm with. You know that I love you. So, will you please relax, because you are driving me crazy.

Leonard: Who you talking to?
Penny: Just this guy I met at school.
Leonard: We're still dating, right?

Sheldon: Get the Mad Hatter on the horn, I'm having a tea party.
Penny: You might want to pace yourself.
Sheldon: I drink tea all the time. I think I know what I'm doing.
Penny: Far be it from me to criticize a man with a full pubis.

Hey, this is my paper. And, my perspective is that slavery is bad. Oh, and my professor's black, so I'm pretty sure that's the right answer.

Amy: You have to be the weirdest couple I know.
Penny: Really? You can't think of anyone weirder?
Amy: I can, [whispers] but she's sitting right there.

Sometimes I forget how smart you are.

Penny: You're unbelievable.
Sheldon: I know.

Amy: Looks like something used by Tinker Bell's gynecologist.
Penny: Who I hope for her sake is not Captain Hook.

Penny: I'm just a blonde monkey to you, aren't I?
Sheldon: You said it, not me.

Penny: We're keeping things, you know, homeostasis.
Amy: It's so cute when she tries.

Sheldon: Penny? Please don't hurt my friend.
Penny: That is the last thing I want to do.
Sheldon: Thank you.

Amy: Soon my upper lip will be the same fake blonde as my beautiful best friend.
Penny: Hey, this is my natural hair color - Now.

TBBT Quotes

Sheldon: I recently read that during World War Two, Joseph Stalin had a research program to create supersoldiers by having women impregnated by gorillas.
Howard: What a sick use of science.
Raj: Hey, as long as the baby's healthy.
Amy: I wonder if Stalin considered any other animals.
Leonard: Hippos are the deadliest creature. A half-human, half-hippo soldier would be pretty badass.
Howard: Yes, but when they're hungry-hungry, you can stop them with marbles.
Sheldon: Yeah, the correct animal for interspecies supersolider is koala. You would wind up with an army so cute it couldn't be attacked.

Raj: Well, to paraphrase Shakespeare: It's better to have loved and lost than to stay home every night and download increasingly shameful pornography.
Penny: Oh... you poor baby.
Raj: What's wrong with me, Penny?
Penny: Nothing, nothing. You know, if we weren't friends - and you hadn't brought up that creepy pornography story - I'd be on you like the speed of light squared on matter to make energy.
Raj: Hey, you totally got that right. E = MC squared.
Penny: I listen. I have no idea what it means, but I listen.