Sheldon: If you're going to replace Wolowitz, I need to know a little bit more about you.
Stuart: All right.
Sheldon: Wolowitz went to MIT. What's your educational background?
Stuart: I went to art school.
Sheldon: Equally ridiculous. Let's go.

Sheldon: Settle down there, fake Wolowitz. No one likes a kiss-up.

Sheldon: Penny, please don't hurt my friend.

Sheldon: Leonard, the transformers teach us that things are not always what they appear to be. You know, like, a semi truck might be an alien robot, or someone in a romantic relationship might feel differently than they appear to.

Sheldon: Excuse me. This is not about protecting my friend. Im a big fan of homeostasis. Do you know what that is?
Penny: Of course not.
Sheldon: Homeostasis refers to a systems ability to regulate its internal environment and maintain a constant condition of properties like temperature or pH.
Penny: Worst bedtime story ever!

Amy: When I get married, I'm going to register at the UCLA Cadaver Lab.
Penny: Eww, why?
Amy: 'cause I've always wanted a whole human skeleton and they are really spendy.

Sheldon: How can she not be sure how she feels? You know, when I have a feeling, I know it. Trains? Love them. Swordfish. I love them, too. They're fish with a sword for a nose.

Howard: The other astronauts are being mean to me.
Bernadette: What are they doing?
Howard: Well, like for instance, the other day when I was asleep, one of the guys went on a space walk and glued a big-eyed rubber alien mask to the outside of my window. When I woke up, I screamed for like nine minutes.
Bernadette: Oh, Howie.
Howard: You can see it if you want. It's on YouTube. Google astronaut screams for nine minutes.

Sheldon: My point is, I don't like when things change. So, regardless of your feelings, I would like you to continue dating Leonard. And also, while we're on the subject, you recently changed your shampoo. I'm not comfortable with the new scent. Please stop this madness and go back to green apple.

Amy: Penny said she's not sure she wants to be Leonard's girlfriend anymore.
Sheldon: Wrong. She just took a sip from his Diet Dr. Pepper.
Amy: So?
Sheldon: So, if she wants to end her pair-bond with Leonard, why on earth would she guzzle a witches' brew of his soda and spit?

Penny: Look, it's fine. We're not getting married, okay? We're keeping things, you know, homeostasis.
Amy: It's so cute when she tries.

Stuart: Raisinet?
Sheldon: Shh, we're trying to watch the movie. (To Amy) This is not working out with him.

Sheldon: *Knock, knock, knock* Leonard? *Knock, knock, knock* Leonard? *Knock, knock, knock* Leonard?
Leonard: What?
Sheldon: Are you sleeping?
Leonard: I was. Now I'm having a nightmare.

Sheldon: Oh, I was having a little trouble sleeping and I just thought, uh, seeing as you're up, we could talk.
Penny: Talk about what?
Sheldon: Oh, I don't know. Uh, weather. Uh, fish you could do carpentry with. Why Leonard is such an attractive and desirable boyfriend. Yeah, pick one. Your choice.
Penny: Sheldon.
Sheldon: Did you know that Leonard has a perfect driving record and enjoys the insurance discounts that go along with that? Hubba-hubba.
Penny: Okay, go home, crazy man.
Sheldon: Yeah. Did you know that while Leonard is not considered a tall fellow in our country, in today's North Korea, he's downright average. Hey, talk about a keeper.

Amy: (Puts Penny on hold, answers a new call) Hello?
Sheldon: Yeah, just a heads-up: Penny knows that you blabbed about Leonard. She's pretty mad.
Amy: I know. She's yelling at me right now.
Sheldon: All right then, so we're all on the same page.

Bernadette: Why don't you stand up to them?
Howard: What am I supposed to say?
Bernadette: I don't know. Say, being mean is lame, what's cool is being nice.

Howard: Great, I'll do that when I want to be the first guy in space to get a wedgie.
Bernadette: Do you want me to call somebody at NASA?
Howard: No. My mom already tried that. It only made things worse.

Raj: Focused Locust.
Stuart: Temple of Yip.
Sheldon: I'm sorry. Wolowitz would never play that card.
Stuart: All right, Lesser Demon Turtle.
Sheldon: Fairy God Monster, I win. Your desperate need for friendship makes you weak.

Raj: So, what are you guys doing later? Stuart and I were thinking of going out for a drink.
Stuart: We're gonna try to meet some girls.
Raj: 'cause that's what we do.
Stuart: Watch out, ladies, a little coffee and cream coming your way.
Raj: In case you didn't follow that, I'm the coffee.

Sheldon: Do you remember how upset I was when they replaced Edward Norton as the Hulk?
Leonard: Yes, you walked around for a week saying, Sheldon unhappy with casting choice.
Sheldon: But, then Mark Ruffalo was the Hulk in The Avengers, and he was even better.
Leonard: What's your point?
Sheldon: Call me a romantic. I like to think that your Mark Ruffalo is still out there somewhere.

Leonard: It'll be fine. Just, uh, pretend he's Wolowitz.
Sheldon: Hmm. Do you like Raisinets?
Stuart: I can take them or leave them.
Sheldon: At the movies, Wolowitz always eats Raisinets.
Stuart: Would you feel more comfortable if I ate Raisinets?
Sheldon: Well, it's hardly my business what you eat. As long as it doesn't crunch during the film and it's Raisinets.

Raj: What's the big deal? You guys are bringing your girlfriends. I didn't want to sit by myself.
Sheldon: The big deal is I was expecting us to be an intimate group of five. Now, we're going to be a faceless mass of six.

Sheldon: Okay, my turn. Let me talk to him.
Leonard: Go ahead.
Sheldon: 2311 North Los Robles Avenue, Pasadena, California to International Space Station. Can you read me? Over. (Makes static noise)
Howard: Yes, I read you, Sheldon.
Sheldon: Copy that. Over. (Static)
Leonard: What are you doing?
Sheldon: I am talking to a man in space. If you don't have the (static) then he might as well be at the Coffee Bean over on Lake Street.
Howard: You're out of your mind, Sheldon!
Sheldon: That's a negative. My mother had me tested. Over.

Amy: You slept with him?
Penny: I didn't know what else to do. He had those big, sad eyes.
Bernadette: Oh, sure, you had no choice.

Sheldon: Leonard, maybe you'd like to go with them to meet girls.
Leonard: Why would I be interested? I have Penny.
Sheldon: Yeah, for now. But that woman has a death wish, Leonard. She talks to strangers, she pets unfamiliar dogs, and it is ridiculously easy to break into her apartment. If I were you, I'd get a back-up.

Leonard: Okay, I think I understand.
Sheldon: You do?
Leonard: The guy who seems like an emotionless robot is you, but your relationship with Amy is causing you to transform into a red-blooded man with sexual desires.
Sheldon: That is literally the stupidest thing I've ever heard.

Sheldon: There's something I need to tell you.
Leonard: Okay.
Sheldon: I can't tell you.
Leonard: Why?
Sheldon: I can't tell you why I can't tell you. So I guess there's two things I can't tell you.
Leonard: I wish there were more.

Sheldon: FYI, secret keeping? Hate it. Hand-holding? Not a fan. Hammerhead shark? I love that thing. Yeah, it's another fish with a tool on its head.

Leonard: Sheldon, you are not in charge.
Sheldon: That's mighty sassy for a man with a roommate performance review around the corner.

Howard: You're out of your mind, Sheldon.
Sheldon: That's a negative. My mother had me tested. Over.

Penny: Amy, you?
Amy: Can't help ya, kid. Whenever I'm around Sheldon, I feel like my loins are on fire. In the good way. Not the urinary tract infection way.

Penny: I'm not unhappy at all. It's just, I don't know, I've been in love before, but it felt different. But maybe this is a new, better, boring kind of love. Do you ever feel that way about Howard?
Bernadette: Oh, that's not really a fair comparison. I'm basically married to a sexy Buzz Lightyear.

Penny: Ooh, one gravy boat.
Amy: That's from Sheldon. He told me he had it engraved.
Bernadette: In the event of divorce, please return to Sheldon Cooper.
Penny: One inappropriate, yet I wish I thought of that, gravy boat.