Raj: They're going to digitally add a supernova they say its the perfect metaphor for my incandescent talent.
Sheldon: Yes, a giant ball of gas that collapses on itself.

Sheldon: I just don't want to be yet another flip-flop fatality.

Sheldon: Oh God, not Euclid Avenue!

Sheldon: It's illegal to spay a human being.

Sheldon: Wait, oh, and I just I want to let you know right now that we are not getting married in a church.
Mary Cooper: That's all right, Sheldon. Anywhere Jesus is is a church.
Sheldon: Well, he won't be at our wedding.
Mary Cooper: He's in my heart, so if I'm there, he'll be there.
Sheldon: Okay, well, then, he's your plus-one. You don't get to bring anyone else.

Sheldon: I agreed to speak to you this evening because I was told that you're the best and the brightest of this university's doctoral candidates. Hmm. Of course, that's like saying you are the most important electron in a hydrogen atom. 'Cause you see, there's only one electron in a hydrogen atom. Best and brightest my sweet patootee. All right, let's begin. Show of hands, who here is familiar with the concept of topological insulators? Don't kid yourselves.

Sheldon: I'm no stanger to mimetic epidemiology. At Johnson Elementary school, the phrase Shelly Cooper's a smelly pooper spread like wildfire.
Amy: I should think so, that's gold.

Sheldon: Look, you may have democracy in your beloved Russia, but on this physics bowl team, I rule with an iron fist. (Raising his fist) Ow!

Sheldon: Like the proverbial cheese, I stand alone. Even while seated.

Sheldon: You know, I've been thinking about time travel again.
Leonard: Why, did you hit a roadblock with invisibility?
Sheldon: Put it on the back burner.

Sheldon: "Gerry the Gerbil and the bully boys on the bus." Read it, not helpful.

Sheldon: All these years I've been so wrong. The tinier the trains, the more concentrated the fun.

Sheldon: Sadly Penny, this evening I am the dark knight roaming these mean streets alone. A windbreaker for my cape and a stern expression for my cowl.

Sheldon: Right now, somewhere, a woman is dividing the atomic weight of the best noble gas by the number of colors in the oldest national flag still in use-
Howard: Then using that number as the average speed to calculate the travel time from Mordor to the Shire.
Sheldon: And taking her first step towards a lifetime of laughter, love and, best of all, rules.

Sheldon: I didn't want to come in. I was told it would make everyone uncomfortable. So I'll just stay out here and pretend I don't need to go to the bathroom.