Sheldon: You just got off the list, would you like back on it?

Sheldon: Someday scientists will discover that second X chromosome contains nothing but nonsense and twaddle.

Sheldon: Howard, what pocket watch will you be wearing for dinner on the train?
Howard: I'm sorry, what?
Sheldon: Well, I'm afraid if we wear the same pocket watch it will be embarrassing.
Howard: I don't own a pocketwatch.
Sheldon: Oh, my. Well my apologies for bringing up this sore spot.

Sheldon: Leonard, have you gotten married yet?
Leonard: No. Why?
Sheldon: Good. Don't do it.
Leonard: Why not?
Sheldon: Some important new information has come to light. Women are the worst. I thought it was paper cuts but I was wrong. No piece of paper ever cut me this deep.

Sheldon: When he finished, he shouted "Eureka"!
Zack: No, I always shouted, "Holy, moly!" Don't know why, just do.

Penny: Where are my clothes?
Sheldon: Your clothes?
Penny: Yes. I left them in the washers and when I went down to get them, they were gone.
Sheldon: Really? Despite the sign that says: "Do not leave laundry unattended?"

Sheldon: I remember it distinctly because I had just finished writing my poem commerating the anniversary of Dr. Seuss's death.
Howard: No one wants to hear it.
Sheldon: Why die? Why did he die? All told, I was told he was old.

Sheldon: It's not a touch phobia, it's a germ phobia. If you'd like to put on a pair of latex gloves I'll let you check me for a hernia.

Sheldon: Leonard, social protocol states when a friend is upset, you offer them a hot beverage, such as tea.
Howard: Tea does sound nice.
Sheldon: You heard the man, Leonard. While you're at it I am upset we have an unannounced house guest, so make me cocoa.

Sheldon: Look on the bright side.
Leonard: What's the bright side?
Sheldon: Only 9 more months to Comic-Con.

TV Announcer: Up next Babylon 5.
(Sheldon looks at Leonard)
(Penny listening to Sheldon and Leonard argue from her apartment)
Leonard: You're not even watching it.
Sheldon: I can hear it.
Leonard: The dialogue offends you?

Christy: Mmm! There's my little engine that could.
*Howard makes train noise*
Sheldon: There's one beloved children's book I'll never read again.

Sheldon: From Hell's heart, I stab at thee!

Sheldon: I'm fine. Although I'm no longer master of my own bladder.

Penny: I'm running really late (to work).
Sheldon: Then I have a simple solution: Go up to the roof, hop over to next building, there's a small gap, don't look if you suffer of vertigo, and use their stairwell.
Penny: You are joking, right?
Sheldon: Oh, I never joke when it comes to vertigo.