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*

Bernadette: You better find my husband's mother, 'cause one way or another we're walking out of this airport with a dead woman.

Howard: I'm sorry I didn't take you to the airport. I just want you to know I'll never forgive myself for being so selfish. And I promise to keep you close for the rest of my life.
Bernadette: Oh, no, that thing's gonna end up in my bedroom.

Bernadette: Gosh, Amy. I'm sensing a little hostility. Is it maybe because like Sheldon's work, your sex life is also theoretical?

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.

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: 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.