Leonard: Oh, I know. This might help. *Gets a ring out of his wallet*
Penny: Where did you get a ring?
Leonard: I've had it for a couple of years. Not important. Penny, will you marry me?
Penny: Oh, my God, yes.
Leonard: This would have been so much more romantic if you didn't have monkey hair on your finger.

Emily: If I saw you out with another woman, I'd be pretty upset.
Raj: Thank you. Not just for being upset, but for believing that could happen.

Amy: (Talking about Howard & Raj) They are going to have sex before Sheldon and I do. I knew it!

Sheldon: A while back, YouTube changed its user interface from a star-based rating system to a thumbs-up rating system. I tell people I'm okay with it, but I'm really not.

Sheldon: I'm writing an appeal to the faculty senate so that I can move on from string theory.
Leonard: How's it going?
Sheldon: You tell me. "Dear esteemed colleagues. As you may know, I have requested to change my field of study. My decision to do so is, I believe, in the best interest of science. At your convenience, I'd be happy to explain it to you in words you'll understand."

Bernadette: So how come you two (Leonard & Raj) didn't move in together?
Leonard: This guy wanted a place of his own because he was sure he was going to be a ladies' man.
Raj: Yeah, I was wrong.

Raj: Cinnamon, she gave me her phone number! If I'd known it was that easy, I'd have considered poisoning you months ago.

Amy: Your husband's weird and his clothes are ridiculous.

Bernadette: It just seems silly for us to sit in two groups.
Leonard: It's not silly if you think of that group as being led by a big, evil baby.

Penny: Look, I'm telling you I've done it. I clearly remember the cow standing up and then a cow on its side.
Leonard: Were you drunk?
Penny: I was sixteen and in Nebraska, what do you think?
Leonard: I think you're the one who fell over.
Penny: Well that would explain why the sky was also on its side.

Leonard: Do you think Penny's mad at me?
Bernadette: Because you're in the right lane behind a bus and you won't go around it? I'm sure she finds it charming.
Leonard: No, because I didn't want her on my team.
Bernadette: I'm starting to think she dodged a bullet. The slowest bullet in the world.

Leonard: Did you get to the chapter where she staged the Easter Egg Hunt with no eggs to see how long I'd keep looking? The answer, by the way, June.

Howard: I lived with her to save money.
Raj: Yeah, you didn't need to buy groceries because you were breast feeding.

Sheldon: My point is we're a couple and I like you for who you are - quirks and all.
Amy: I like you too.
Sheldon: I should hope so. I don't see anybody else banging on this door to put up with your nonsense.
*Amy slams the door on Sheldon*
Sheldon: Not even a goodbye? You see this is the kind of thing that makes people think you're weird. ... Poor kid. She just doesn't see it.

Sheldon: I hate to pile on the bad news, but I just got a raise.