Sheldon: Hummingbirds are the vampires of the flower world.
Raj: Still my first choice for an ankle tattoo. Or, a dolphin -- I go back and forth.

Raj: Come on, Sheldon, Star Wars.
Howard: I'm pushing play. I mean it. If we don't start soon, George Lucas is going to change it again.

Tickets are 11 bucks. Not a date.

Leonard

Leonard: No. You always picked and it was always the same. An hour and a half of beach houses in the rain until the woman turns around and realizes love was here all along.
Penny: But, come on, that was a great movie and it starts in ten minutes.

Leonard: Too casual?
Sheldon: For an audience with the queen, yes. For an evening of passing a bottle of fortified wine around a flaming trash can, you look great.

Leonard: I'm going to the movies with Penny. I don't want her to think I think it's a date
Sheldon: Do you think it's a date?
Leonard: No, but she might think I think it's a date even though I don't.
Sheldon: Or you might think she thinks you think it's a date even though she doesn't.
Leonard: Are we over thinking this?
Sheldon: Not at all.

Penny: And,remember he's more afraid of you than you are of him.
Sheldon: That doesn't help.
Penny: No, I was talking to the bird.

Leonard: Star Wars on Blu-ray.
Penny: Haven't you seen that movie like a thousand times?
Leonard: Not on Blu-ray. Only twice on Blu-ray.
Penny: Oh, Leonard.
Leonard: I know, it's high resolution sadness.

Whee! Ooh, finally someone found second base.

Amy

Leonard: Why do I have to talk to Penny? She's not my girlfriend.
Sheldon: You invited her to lunch four years ago, everything about her is on you: you make it so!

Howard: What do you want us to do about it?
Sheldon: You clearly weren't listening to my topic sentence: Get your women in line!

Last night, I was strong-armed into an evening of harp music and spooning with an emotional Amy Farrah Fowler. This on a night that I had originally designated for solving the space-time geometry in higher-spin gravity and building my Lego Death Star. And why? Your gal pals, Penny and Bernadette went out shopping for some wedding nonsense without Amy, an action they took with no thought or regard as to how it would affect me, the future of string theory, or my lego fun time!

Sheldon

The Big Bang Theory Season 5 Quotes

You can't blame yourself. When your prefrontal cortex fails to make you happy promiscuity rewards you with the needed flood of dopamine. We, neurobiologists, refer to this as the skank reflex.

Amy

I feel like two totally different people. Dr. Jekyyl and Mrs. Whore.

Penny