Sheldon: Oh, tweets about my lecture. Hmm. That's rather unfair. That's downright cruel. Plus, insects have six legs. Yeah, I'm not familiar with the acronym KMN.
Leonard: Oh, uh, from the context, we think it means kill me now.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

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.