Leonard: But I did realize something. I-I don't need to fight your battles. You you are a strong and independent woman. You have your own voice. And, to quote another strong woman, Katy Perry, it's time to hear you roar.
Penny: Did you just think of that on your way home?
Leonard: What do you want from me? The song was on in the car. But it doesn't mean that it's not true.

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?

Stuart: Listen to this. I-I was ringing up a customer, and I heard someone say, "Hey, there's a line," and I looked, and there was.

Stuart: Oh, look at that. Neil Gaiman tweeted about my store!
Howard: What did he say? Uh, "Next time you're in Pasadena, check out The Comic Center. Great vibe, old school, the owner really knows his stuff." Isn't that amazing?
Sheldon: Well, uh, it's no Sandman, but I guess we can't expect everything he writes to be a masterpiece.

Sheldon: Can you see Mercury? Can you see it?
Raj: One second.
Amy: You know, the Greek version of Mercury, Hermes, was worshipped in Athens by the carving of giant wooden phalluses.
Sheldon: Please, Amy, get your mind out of the ancient Athenian gutter.