Bernadette: I'm too small for Twister. And roller coasters. And sitting with my feet on the floor. Hope you enjoyed the prenatal cigarettes, Mom.

(Sheldon knocks on Penny's door three times)
Penny: Who do we love?
Sheldon: Penny. (Knocks 3 times)
Penny: Who do we love?
Sheldon: Penny. (Knocks 3 times)
Penny: Who do we love?
Sheldon: Penny.

Howard: I thought you didn't like Facebook any more.
Sheldon: Don't be silly, I'm a fan of anything that tries to replace actual human contact.

Bernadette: Doesn't he know you have a boyfriend?
Penny: She doesn't have a boyfriend, she has a Sheldon.

Sheldon: I believe I would like to alter the paradigm of our relationship.
Amy: I'm listening.
Sheldon: With the understanding that nothing changes what so ever - physical or otherwise, I would not object to us no longer characterizing you as not my girlfriend.
Amy: Interesting, now try it without the quadruple negative.

Sheldon: I'm the guy.
Penny: You're not the guy.
Sheldon: Are you sure? It would explain so much. Your constant presence in my apartment. That baffling dalliance with Leonard just to be near me. The way you call me sweetie all the time.
Penny: I call everyone sweetie.
Sheldon: You tramp.

Sheldon: I present to you the Relationship Agreement. A binding covenant that in its 31 pages enumerates, illuminates and codifies the responsibilities of Sheldon Lee Cooper - hereinafter referred to as the "Boyfriend" - and Amy Farrah Fowler - hereinafter referred to as the "Girlfriend.
Amy: That's so romantic!
Sheldon: Mutual indemnification always is.

Stuart: I'll ring it up. It's like shooting nerds in a barrel.

Stuart: Can I help you find anything?
Amy: A comic that doesn't depict a woman whose bosom can be used as a flotation device.

Sheldon: I got a splinter.
Amy: What do you want me to do about it?
Sheldon: Relationship Agreement - Section 4: Boo-boos and Ouchies. You have to take care of it.
Amy: I should've gotten a lawyer.

Penny: Strap on a pair and go talk to Amy.
Sheldon: Strap on a pair of what? ...Skates?
Penny: Oh, you are so not the guy.

Amy: Goodnight, Stuart.
Stuart: Goodnight.
*Stuart and Amy hug*
Sheldon: (From inside Amy's apartment) Take the hint, Stuart, the lady said goodnight!

Sheldon: I'm not sure how to respond, Leonard. I don't own Amy. You can't own a person, at least not since?
*Leonard stares at him*
Sheldon: 1863. When President Lincoln freed the?
*Leonard looks fed up*
Sheldon: Slaves. Come on, Leonard. If you're gonna teach history, these are the kind of facts you'll have to know.

Amy: (Reading Sheldon's relationship agreement) Section 5, Hand Holding: Hand holding is only allowed under the following circumstances: A. either party is in danger of falling of a cliff, precipice or ledge; B. either party is deserving of a hearty hand shake after winning a Nobel prize; C. moral support during flu shots.

Howard: You interested in Amy?
Stuart: Well, I mean she didn't look through me with soul-sucking ball-shriveling hatred and contempt. I like that in a woman.