Sheldon: *knocks three times* Amy, Bernadette, Penny. *repeats three times*
Bernadette: He's never going to stop doing that, is he?
Amy: I don't mind. I'm hoping to put his love of repetition to good use someday.

Howard: My arm is feeling numb. *Howard rubs his right arm*
Bernadette: That's the wrong arm for a heart-attack, doofus.
*Howard switches to his left arm*

Amy: It's actually steamier than it looks. Sheldon's looking up the phallic symbolism of root vegetables in renaissance paintings.
Sheldon: Oh no, I got bored of that. I'm just browsing cuticle scissors on Amazon.

Sheldon: Maybe your friend Gundersen needs to head over to IKEA and assemble a sense of humor.

Sheldon: Amy, this isn't easy to say. All relationships are difficult. But even more so when you're with a person who struggles with everyday social interactions. And frankly, who can strike people as being kind of a weirdo.
Amy: Sheldon, you're not a weirdo.
Sheldon: I wasn't speaking about me. I mean, honestly, there's no telling what will set you off. Introducing myself as your boyfriend. Giving you the opportunity to drive me home. Breaking the ice with you colleagues using ethnic humor - the funniest kind of humor.

Raj: His only options here are to fake a heart attack or have a real one.

Sheldon: That's right. I'm in a boy-girl relationship with this cute little lump of wool.

Sheldon: It's a physical relationship, too. With hand-holding, hugging - even on hot days! ... Oww! Here's a new one, apparently we kick each other on the shins under the table.

Sheldon: Are you sure your moth-like personality won't be drawn to this blazing fire that is myself?
Amy: More and more sure.

Amy: I have some exciting news to tell you.
Sheldon: That makes two of us. My new cuticle scissors will be here in one to two business days. ... Come on, one.

Raj: It wasn't a pajama party. It was just a couple of bros hanging out, giggling, eating cookie dough and watching Princess Bride.
Howard: Please stop talking.
Raj: As you wish.

Sheldon: If you're hungry, I brought home mutton and coconut milk.
Penny: Why'd you do that? You hate lamb.
Sheldon: I was asking for directions. Apparently there was a communication problem.

Sheldon: My point is we're a couple and I like you for who you are - quirks and all.
Amy: I like you too.
Sheldon: I should hope so. I don't see anybody else banging on this door to put up with your nonsense.
*Amy slams the door on Sheldon*
Sheldon: Not even a goodbye? You see this is the kind of thing that makes people think you're weird. ... Poor kid. She just doesn't see it.

Penny: You can't tell her what she can or can not do.
Sheldon: Last week you told Leonard he couldn't wear his wookie jacket out in public.
Penny: That's different. I'm not going to the mall with somebody dressed like a dumb space bear.

Leonard: I thought Amy was going to drive you home.
Sheldon: I thought so too, but she's acting very strangely. I was discussing it with a Sri Lankan fella on the bus. He hypothosized that a tiger may have recently run across her shadow. Although he may have just been trying to drum up business for his brother-in-law's witchdoctor practice.