Howard: Look. Listen to this one. Does Einstein's theory explain why time flies when you're having fun, but when you're listening to Dr. Cooper, it falls out of the sky, dead?

Howard: You know, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

Howard: So you can never take it (the sweater) off?
Leonard: No.
Raj: Not even to sleep?
Leonard: No.
Howard: So you're just an idiot?
Leonard: It's called proving a point.
Howard: Is the point you're an idiot?

Bernadette: Does your mother call you every day at work to see if you had a healthy lunch?
Howard: My mother calls me every day at work to see if I had a healthy bowel movement.

Raj: Dance number aside, I'm so not gay.

Penny: Mrs. Cooper? Hey, it's Penny. I think I broke your son. Hold on. Talk to your mother.
Sheldon: (Crying) Mommy, I love you. Don't let Spock take me to the future!

Raj: I know the feeling. It's like accidentally walking into a gay bar and then having no one hit on you. It happened to a friend of mine.