Sheldon: In Texas, when a cow stops giving milk, they don't continue feeding her. They take her out and shoot her between the eyes.
Penny: I'm confused. Did Sheldon stop giving milk?

Leonard: You always knew that someday someone would come along who was younger and smarter.
Sheldon: Yes, but I assumed I would have been dead hundreds of years and that there'd be an asterisk next to his name because he'd be a cyborg

Engineering, where the semi-skilled laborers execute the vision of those who think and dream

Sheldon

Raj [referring to Dennis Kim]: Do you know what he did? He watched me work for ten minutes and then started to design a simple piece of software that could replace me.
Leonard: Is that even possible?
Raj: As it turns out, yes

Sheldon: What happens if you use argon lasers instead of helium-neon?
Leonard: It would blow up!
Sheldon: Are you sure?
Leonard: Pretty sure...
Sheldon: Pretty sure? It's not very scientific. Is this how you normally work? Just hunches and guesses and stuff?

Raj: We need a social catalyst.
Leonard: Like what? We can't get 15-year-old girls drunk.
Wolowitz: Or can we...!?

Sheldon: Here's the problem with teleportation.
Leonard: Lay it on me.
Sheldon: Assuming a device could be invented, which would identify the quantum state of matter of an individual in one location and transmit that pattern to a distant location for reassembly. You would not have actually transported the individual, you would have destroyed him in one location and recreated him in another.
Leonard: How about that.
Sheldon: Personally, I would never use a transporter because the original Sheldon would have to be dissintegrated in order to create a new Sheldon.
Leonard: Would the new Sheldon be in any way an improvement on the old Sheldon?
Sheldon: No, he would be exactly the same.
Leonard: That is a problem

Leonard: Come on, Dennis, I'll show you the rec center. They've got Nautilus equipment.
Dennis: Do I look like I lift weights?
Leonard: Not heavy ones

Ladies and gentlemen... honored daughters... while Mr. Kim, by virtue of his youth and naivety, has fallen prey to the inexplicable need for human contact, let me step in and assure you that my research will go on uninterrupted and that social relationships will continue to baffle and repulse me. Thank you

Sheldon

Wolowitz: We need a hot 15-year-old Asian girl with a thing for smart guys.
Penny: What?
Leonard: Howard, that's racist. Any fifteen year old girl will do the trick

If we were in India this would be simpler. Five minutes with her dad, 20 goats and a laptop, and it would be done

Raj [on approaching a girl]

Leonard: You speak English really well.
Dennis: So do you... except for your tendency to end sentences with prepositions.
Leonard: What are you talking about?
Dennis: That.
Sheldon: He's not wrong

The Big Bang Theory Season 1 Quotes

Penny: What actor holds the record for being named People magazine's Sexiest Man Alive?
Sheldon: William Shatner!
Leonard: I don't think it's Shatner.
Sheldon: Then it's got to be Patrick Stewart

I made chicken. I hope it's not one of the animals that you people think is magic

Mary [to Raj]