Leonard: Sometimes your movements are so lifelike I forget you are not a real boy.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Raj: Oh, you're so arrogant. If you were a super hero your name would be Captain Arrogant. And do you know what your super power would be? Arrogance.

Sheldon: Oh, Penny. Penny.
Penny: What's up?
Sheldon: Nothing. I just wanted to make Raj stop talking.

Raj: Sorry, dude. The thermostat's on my side of the room, so it stays Mumbai hot in here until you turn off that stupid Indian music.
Sheldon: I'll turn off the music when you get rid of that salmonella-ridden parakeet.
Raj: Oh, too bad. Sheldon's pathologically afraid of birds. Hey, look, Sheldon. Birdie, birdie, birdie.
Sheldon: That's it. Prepare for marshmallow death.
Raj: Eat flaming Nerf.