Penny: Helium.
Sheldon: Yes.
Penny: Yes.
Sheldon: Taylor Swift.
Penny: Yes. Pi.
Sheldon: Yes. Kardashian.
Penny: More specific.
Sheldon: Khloe?
Penny: Yes.
Sheldon: See, I remembered because if it looks like Kim it's Kim, if it looks kind of like Kim it's Kourtney, and if it looks nothing like Kim it's Khloe.

Sheldon: Sorry I'm late. I also got you a balloon, but it floated away and I chased it for a while.

Bernadette: Yeah, it's your third date, maybe you could go more sexy.
Amy: Well, some people think the sexiest organ is the brain.
Penny: No one ever bought me drinks at a bar because my brain just popped out of my shirt.

Penny: Oh, my God, he won't stop.
Leonard: How does he keep coming up with new ways to be annoying?
Penny: Nobody knows. That's why he's number one.

Wil Wheaton: Hey, Sheldon. This is Adam Nimoy.
Adam Nimoy: Nice to meet you.
Sheldon: Oh, it's nice to meet you. I admire your father's work very much.
It's not every day I get to meet someone whose life's journey began in my hero's scrotum.

Amy: Sheldon, what's wrong?
Sheldon: I wanted to let you know I'll be spending your birthday with you.
Amy: Okay.
Sheldon: See, I had tickets to the Star Wars premiere that night, but Professor Proton came to me in a dream, dressed as Obi-Wan Kenobi, and convinced me that I should be with you.
Amy: Obi-what?
Sheldon: I'll let you get back to sleep now. Good night.
Amy: Good night. Uh, Sheldon, were you actually not going to spend my birthday with me?
Sheldon: (feigning sleepiness) It's late, gotta go, bye.

Leslie Winkle: Uh, in the past, I would've said something obnoxious, like, "Happy birthday, dumbass". But I'm not gonna do it. You and I have both grown a lot, and it's just so nice to see you all again. So happy birthday, Sheldon.
Sheldon: Oh. Oh, now, you know I hate change. Say it.
Leslie Winkle: Happy birthday, dumbass!

Leonard: I love you.
Penny: Who cares?

Stuart: Anyone else need anything before I go?
Howard: I'll give you a dollar if you make fun of Raj.
Stuart: That's mean.
Howard: Five.
Stuart: You look like Tigger if Tigger looked like a jackass.
Howard: Uh, if you ever need a reference or anything, just let me know.

Raj: You're not wrong about Fruit Stripe. I-I was always a Hubba Bubba man.
Howard: Hubba Bubba over Dubble Bubble? You're crazy.
Raj: Hey, the jaw wants what it wants.

Raj: Boy, all this standing's making me tired. Good thing I brought my collapsible stick chair.
Howard: Not the stick chair. You look like an idiot on that thing.
Raj: Sticks and stones may break my bones, but chairs on sticks are comfy.

Amy: Let's see. I have been on six dates with three different people. It was either for coffee or dinner. One I met at a bookstore and two I met online. I haven't slept with anyone. The aquarium is 40 minutes away. And there's a baggie of Cheerios for you in the glove compartment.
Sheldon: Uh, regular or honey nut?
Amy: I mixed them.
Sheldon: You mixed them. No wonder gentleman callers are pounding down your door.

Sheldon: Your friends? I think you mean my friends. And why wasn't I invited to this?
Amy: Maybe because the two of us being there would make them feel awkward.
Sheldon: We make everyone feel awkward. That's our thing!

Penny: I think it's so adorable you're making Sheldon breakfast.
Leonard: Well, he's having a rough time. Amy broke his heart, the DVR cut off the last minute of Doctor Who, that crow followed him home.

Sheldon: I understand that we are no longer a couple, but I'd like to remind you that we made a baby together.
Amy: What baby?
Sheldon: A precocious, little Internet show known as Fun with Flags.