Sheldon Cooper

Sheldon Cooper: Everybody's got a date. Even you, Mario, going after Princess Peach. And what am I doing? I'm just enabling you.

[Leonard is depressed over seeing Penny with another guy and is handling it by listening to emo music and considering buying a cat. He enters with headphones on singing "Boston" by Augustana, badly]
Leonard: 'She said you don't know me, you don't even care, oh yeah... '
Sheldon: Oh, good Lord.
Leonard: 'She said you don't know me, you don't wear my chaaaiiins, oh yeah... '
[takes off headphones]
Leonard: That's a good song!
Sheldon: If you're compiling a mix CD for a double suicide.

Leonard: So, tell us about you.
Penny: Um, me? Okay - I'm a Sagittarius, which probably tells you way more than you need to know.
Sheldon: Yes - it tells us that you participate in the mass cultural delusion that the sun's apparent position relative to arbitrarily defined constellations at the time of your birth somehow affects your personality.
Penny: [stares at Sheldon in utter confusion] Participateinthewhat?
Leonard: [scrambling to save face] I think what Sheldon is trying to say is that Sagittarius wouldn't have been our first guess.
Penny: Oh, yeah - lot of people think I'm a water sign.

Sheldon: You're not done with her, are you?
Leonard: Our babies will be smart AND beautiful.
Sheldon: Not to mention imaginary.

Rajnesh Koothrappali: [Attempting to determine which Sci-fi show to watch the two heroes expand the rock-paper-scissors game] I'll tell you what. How about we go rock-paper-scissors?
Sheldon Cooper: Ooh, I don't think so. Anecdotal evidence suggests that in the game of rock-paper-scissors, players familiar with each other will tie 75 to 80% of the time due to the limited number of outcomes. I suggest rock-paper-scissors-lizard-Spock.
Rajnesh Koothrappali: What?
Sheldon Cooper: It's very simple. Scissors cuts paper. Paper covers rock. Rock crushes lizard. Lizard poisons Spock. Spock smashes scissors. Scissors decapitates lizard. Lizard eats paper. Paper disproves Spock. Spock vaporizes rock. And as it always has, rock crushes scissors.

Rajnesh Koothrappali: So, who gets the extra dumpling?
Rajnesh Koothrappali, Sheldon Cooper, Howard Wolowitz: Rock, paper, scissors, lizard, Spock!
Rajnesh Koothrappali, Sheldon Cooper, Howard Wolowitz: [They all draw Spock] Ahh!
Sheldon Cooper: Okay, one of us has to stop putting up Spock.
Howard Wolowitz: How do we decide?
Rajnesh Koothrappali, Sheldon Cooper, Howard Wolowitz: Rock, paper, scissors, lizard, Spock!
Rajnesh Koothrappali, Sheldon Cooper, Howard Wolowitz: [They all draw Spock again] Ahh!