The Big Bang Theory Season 2 Episode 15

Sheldon: I've always hated how my right frontal lobe looks in pictures.
Beverly: Common complaint among men—nothing's ever big enough. Except when they get a tumor—then you don't hear the end of it.

Penny: What was Leonard like when he was little?
Beverly: Oh, I think you mean young. He's always been little.

Penny: Wait, wait, [Beverly] is not going to come here looking for you, is she?
Leonard: Relax, she took Sheldon into a hospital to get a brain scan.
Penny: Oh, my God, what happened?
Leonard: Nothing. Mother likes looking at brains, and Sheldon likes getting his brain scanned.

Leonard: Howard lives with his mother, and Raj can't speak to women unless he's drunk. Go!
Beverly: Oh, that's fascinating. Selective mutism is quite rare. On the other hand, an adult Jewish male living with his mother is so common, it borders on sociological cliché.
Howard: It's just temporary. I pay rent.
Leonard: He lives in the same room where his bassinet was.
Beverly: You know, both selective mutism and an inability to separate from one's mother can stem from a pathological fear of women. It might explain why the two of you have created an ersatz homosexual marriage to satisfy your need for intimacy.
Howard: Say what?

Beverly: Your uncle Floyd died.
Leonard: Oh, my god, what happened?
Beverly: His heart stopped beating.

(Penny complains while the gang plays Rock Band)
Howard: Penny, come on, we're just finding our sound.
Penny: You found it. It's the sound of a cat being run over by a lawn mower

Penny: You must be Leonard's mother.
Beverly: I don't know if I must be, but yes.

Sheldon: I would very much like to read about your sex life.
Beverly: Well, it's all on-line.