Sheldon: Your check-engine light is on.
Penny: Uh huh.
Sheldon: Typically, that's an indicator to, you know, check your engine.
Penny: It's fine. It's been on for like a month.
Sheldon: Well, actually that would be all the more reason to, you know, check your engine.
Penny: Sheldon, it's fine.
Sheldon: If it were fine, the light wouldn't be on. That's why the manufacturer installed that light, to let you know it's not fine.
Penny: Maybe the light's broken.
Sheldon: Is there a check-the-check-engine-light light?

Sheldon: And you thought the opposite of stupid loser was a Community College Graduate?

Sheldon: You seem to have forgotten the reason we live together is that we're best friends. And I've got your back, Jack.

Leonard: Sheldon, this is not your home!
Sheldon: This isn't anyone's 'home'. This is a swirling vortex of entropy.

Penny: Whatcha doin'?
Sheldon: I'm attempting to view my work as a fleeting peripheral image so as to engage the superior coliculus of my brain.
Penny: Interesting. I usually just have coffee. Have you been up all night?
Sheldon: Is it morning?
Penny: Yes.
Sheldon: Then I've been up all night.

Sheldon: Leonard, the people at Nintendo can only go so far in helping us recreate an actual athletic experience. We have to do our part too.

Sheldon: *On computer screen* Greetings, hamburger toucher. You are probably wondering why you cannot IM with your little friends about how much you heart various things. Well, this recorded message is alerting you that I am putting an end to your parasitic piggybacking upon our WiFi. If you want to remedy the situation you can contact the phone company, set up your own WiFi and pay for it, or you may apologize to me.

Sheldon: Wine and a girl in the dark. He's going to be bored out of his mind.

Leonard: Will you stay out of this?
Sheldon: If only Penny had said that once in a while.

Sheldon: (To Amy) Do you have any idea what it's like to wait for years and never know if you're finally going to get satisfaction?

*Sheldon spots Amy Farrah Fowler outside the apartment*
Sheldon: Oh dear... they really do be crazy.

Sheldon: Good grief. It's like talking to a dolphin.

Amy: Gentlemen, as much as I'm sure Sheldon would enjoy playing intergalactic make-believe, he and I have other plans. We are attending my Aunt Flora's 93rd birthday party. Sheldon: Just tell her I can't come. Amy: She'll be disappointed if we don't show up. Sheldon: She's 93. She won't be disappointed for very long.

Sheldon: Penny for your thoughts?

Sheldon: You know, it's amazing how many super villains have advanced degrees. Graduate schools should do a better job of screening those people out.