Raj: Hey, Sheldon, guess what I've heard today.
Sheldon: I'd imagine you heard any number of things today. When you arrived at work, you undoubtedly heard: Hello, Raj; How are you, Raj; and given you're wearing a new sweater vest, you may have heard: "New Sweater Vest" and possible, though less likely "Nice Sweater Vest."

Amy: And this is Dr. Gundersen from Stockholm.
Sheldon: Ah, Sweden. Home of my favorite Muppet and second-favorite meatball.
*Dr. Gundersen and Amy look blankly at Sheldon*
Sheldon: Okay, the Nordic reputation for a lack of humor is well founded. Boy, is his name Gundersen or No-fun-dersen?

Sheldon: Okay, I know you're texting about me and I'd really like you to stop.

Sheldon: Oh, and FYI, if you cry while they're fighting they'll take you to McDonald's.

Sheldon: Thank you for letting me come speak with you.
Bernadette: Of course.
Sheldon: As my relationships with Penny and Amy are currently strained, I'm turning to you for female comfort and encouragement.
Bernadette: Aww, I'm honored.
Sheldon: I tried reaching out to my mother, but she was in Bible study. Leonard's mother is on a book tour. My Mee-Maw was taking a nap. And after a while Siri started repeating her answers.
Bernadette: So, I'm your seventh choice.
Sheldon: Yeah, I know, top ten. Pretty exciting.

Leonard: Sheldon has kind of a photographic memory.
Sheldon: "Photographic" is a misnomer. I have an eidetic memory, as I've told you many times. Most recently last year during lunch on the afternoon of May 7th. You had turkey and complained it was dry.

Penny: You know, you go on and on about wanting things to stay the same, but you've changed a lot since I met you.
Sheldon: Oh, you are a mean drunk.

Wil Wheaton: Sheldon, I promise that I will work my hardest to make this show great so that a whole new generation of kids will grow up and they will be able to say that Professor Proton was the reason they got into science.
Sheldon: Wow, that was very persuasive.
Wil Wheaton: Thanks.
Sheldon: But I won't be seduced by your acting skills nor your movie star charisma. There's only one Professor Proton, and he had neither of those things.

Sheldon: I'm so proud of you.
Amy: And I'm proud of you.
Sheldon: Because you can't tell how jealous I am?
Amy: No, no, no. I can. But I can tell how hard you're trying to keep it in.
Sheldon: Really hard.
Amy: I'm gonna go to bed.
Sheldon: All right, I'm gonna go scream on the roof.

Leonard: Do you have a cousin Leopold?
Sheldon: No, I made him up. I think you'd call him Lee.
Leonard: I don't get it. I already told her a lie. Why replace it with a different lie?
Sheldon: Well, first of all, your lie was laughably transparent, where mine is exquisitely convoluted. While you were sleeping I was weaving an un-unravelable web.
Leonard: un-unravelable?
Sheldon: Yes, if she Googles "Leopold Houston" she'll find a Facebook page, an online blog depicting his descent into drug use, and a desperate yet hopeful listing on e-Harmony.com.

Sheldon: Beverly believes I unconsciously consider my old room an escape hatch.
Amy: Is that bothering you?
Sheldon: Yes. I don't care for unconscious thoughts. My brain and I are best friends. It should tell me everything.
Amy: I mean, how it relates to our relationship, not the bromance between you and your brain.

Leonard: See, the liquid metal Terminators were created in the future by Skynet, and Skynet was developed by Miles Dyson, but that future no longer exists due to Dyson's death in Terminator 2.
Sheldon: Okay, then riddle me this. Assuming all the good Terminators were originally evil Terminators created by Skynet but then reprogrammed by the future John Connor, why would Skynet, an artificial computer intelligence, bother to create a petite hot 17 year-old killer robot?
Leonard: Skynet is kinky? I don't know.
Sheldon: Artificial intelligences do not have teen fetishes.

Sheldon: Alright, I'm mad at you. Not only did you ruin Raiders for me, you might have ruined the whole franchise. Except for the fourth one, which was bad before you got your mitts on it.

Bert: Sheldon, you left your jacket in my office last night.
Sheldon: Uh, oh. No-no, I didn't. That's-that's not my jacket.
Leonard: Then why does it say, "Property of S. Cooper. Stop touching it."?
Sheldon: It sounds like someone named Scooper doesn't want you touching his jacket.

Amy: Is it from one of your dumb sci-fi shows?
Sheldon: Uh, none of the sci-fi shows I watch are dumb.
Amy: Sheldon.
Sheldon: Okay, Westworld. But this has nothing to do with that show, other than it's also inexplicable.