Sheldon: So Leonard, how goes the mimesis?
Leonard: Mimesis?
Sheldon: You know. Mimesis. An action in which the mimic takes on the properties of a specific object or organism. Mimesis.
Leonard: What the hell are you talking about?
Sheldon: I'm attempting to communicate with you without my meaning becoming apparent to those around you. Let me try again. Have the indigenous fauna accepted you as one of their own? Nudge, nudge, wink, wink.

Sheldon: Die, Wil Wheaton, die!

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

Sheldon: Now Fetch Me Will Wheaton! (SPEAKING KLINGON)
Wil Wheaton: Did that guy just say, "Revenge is a dish best served cold," in Klingon?
Stuart: I believe so.
Wil Wheaton: What is wrong with him?
Stuart: Everyone has a different theory.

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.

Leonard: Can I have a napkin.
Sheldon: I'm sorry, no!
Leonard: But you have a whole bunch of napkins.
Sheldon: Yes, I've moved to a four napkin system, lap, hands, face, and personal emergency. If you like, starting tomorrow, I'll add a guest napkin but I'm afraid there's nothing I can do for you today.
*Leonard grabs a napkin.*
Sheldon: Good luck, that's the face napkin.

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."

Sheldon: (To Stuart) I can buy all these things online, I come here for the personal service.

Sheldon: Excuse me, are you saying that Wil Wheaton, a.k.a. Ensign Wesley Crusher on Star Trek: The Next Generation, is going to be participating in your tournament?
Stuart: I'm sorry, did I rob you of the opportunity to stumble onto that for yourself?
Sheldon: No, wait, you don't understand. Growing up, I idolized Wil Wheaton. You know, Wesley Crusher had an eidetic memory just like me.
Raj: Oh, what a coincidence. Maybe you can discuss that with him while you're playing in the tournament. Sign here.
Sheldon: Yeah, I was such a fan that in 1995, I traveled 10 hours by bus to a sci-fi convention in Jackson, Mississippi wearing my Starfleet Academy cadet uniform in order to meet Wil Wheaton and get him to autograph my mint-in-package Wesley Crusher action figure.
Raj: Oh, It'll be like a reunion then. Sign here.
Sheldon: (Mood changes) Yeah, my arduous journey, however, was for naught. Although advertised to appear, he did not show up. It was at that moment I vowed eternal hatred for Wil Wheaton.
Raj: Okay, great, you can tell him you hate him, sign here.
Sheldon: It might interest you to know that Wil Wheaton currently ranks 6th on my all-time enemies list, right between director Joel Schumacher, who nearly destroyed the Batman movie franchise, and Billy Sparks, who lived down the street from me and put dog poop on the handles of my bicycle.

Sheldon: In the words of Khan Noonien Singh in the immortal Wrath of Khan: "He tasks me, he tasks me and I shall have him."
Raj: No doubt! Sign here.
Sheldon: (Signing) "From hell's heart, I stab at thee."

Sheldon: The year was 1995, the place, Jackson, Mississippi, having spent 10 hours on a bus, during which I had to twice violate my personal rule against relieving myself onboard a moving vehicle, I finally arrived at the 4th annual Dixie Trek Convention only to find that my idol, Wil Wheaton, decided he had better things to do than show up and sign my action figure.
Wil Wheaton: What?!
Sheldon: You betrayed me, Wil Wheaton, now I have my revenge.

Sheldon: Yes, since their relationship became carnal, Penny has updated his designated term of endearment, distinguishing him from those she calls 'sweetie,' usually as an attempt to soften a thinly-veiled insult.
Penny: You're boring people, sweetie.
Sheldon: Although sometimes, she omits the veil entirely.

Sheldon: Like the subordinate male protagonist in countless action movies who disappears halfway through the second reel, I have returned to save the day. [pause]. Odd, he's usually met by cheers.

Sheldon: There's a fine line between wrong and visionary. Unfortunately, you have to be a visionary to see it.

Raj: You want me to work with you?
Sheldon: For me!