Sheldon: Please, please, I don't have a lot of time. Ramona finally dozed off and I need you to help me get rid of her.
Penny: Get rid of her how?
Sheldon: I don't know, but apparently I'm in some kind of relationship, and you seem to be an expert at ending them.
Penny: Excuse me?
Sheldon: I see man after man leaving this apartment, never to return.

Sheldon: How am I going to get to work?
Leonard: Take the bus.
Sheldon: Oh, I can't take the bus anymore. They don't have seatbelts, and they won't
let you lash yourself to the seat with bungee cords.
Leonard: You tried to lash yourself to the seat with bungee cords?
Sheldon: I didn't try; I succeeded.

Sheldon: Leonard, have you ever wondered why my little toes and lateral incisors are significantly smaller than the average for someone of my size?
Leonard: I wonder a lot of things about you Sheldon, but not that

Leonard: It wouldn't kill us to meet new people.
Sheldon: For the record, it could kill us to meet new people

Leonard: If we do get a new friend, he should be a guy you can trust. You know, a guy who has your back.
Wolowitz: And he should have a lot of money and live in a cool place down by the beach where we could throw parties.
Sheldon: And he should share our love of technology.
Wolowitz: And he should know a lot of women.
Leonard: Okay, let's see: money, women, technology. Okay, we're agreed. Our new friend is going to be Iron Man

Penny: What's AFK?
Sheldon: Away From Keyboard.
Penny: Oh, I see.
Sheldon: What does that stand for?

Penny: Oh, my God, a treasure chest. I'm rich!
Sheldon: Level 3 and she thinks she's rich, what a noob.

Raj [to Leonard]: What about Leslie Winkle?
Sheldon: Oh, no.
Raj: Why?
Sheldon: Her research methodology is sloppy, she's unjustifiably arrogant about loop quantum gravity, and to make matters worse, she's often mean to me

Everybody has a date. Even you Mario, going after Princess Peach. What am I doing? I'm just enabling you.

Sheldon: Why should I leave? This is my apartment, too.
Leonard: I know it is. And if science ever discovers a second member of your species, and you two would like some privacy, I'll be more than happy to get out of your way

Leonard: How could you just sit there and let them spy on me?
Sheldon: They were clever, Leonard. They exploited my complete lack of interest in what you were doing

Sheldon: You're asking me to keep a secret?
Penny: Yeah.
Sheldon: Well, I'm sorry, but you would have had to express that desire before revealing the secret, so that I could choose whether or not I wanted to accept the covenant of secret-keeping. You can't impose a secret on an ex post facto basis.
Penny: What?
Sheldon: Secret-keeping is a complicated endeavor. One has to be concerned not only about what one says, but about facial expressions, autonomic reflexes. When I try to deceive, I myself have more nervous tics then a Lyme disease research facility.... It's a joke. It relies on the homonymic relationship between "tick," the bloodsucking arachnid, and "tic," the involuntary muscular contraction. I made it up myself

TBBT Quotes

Penny: 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: Participate in the what?

Penny: Hey, Sheldon, did you change your Wi-Fi password again?
Sheldon: Yes, it's "Penny, get your own Wi-Fi." No spaces.