Penny: Hey, Leonard, is your wi-fi down? I can't get on.
Leonard: Oh, Sheldon changed the password. It's now Penny is a freeloader. No spaces.

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.

Leonard: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

Sheldon: Well, I suppose everyone's entitled to their own opinion. I think I'll turn in. I didn't wanna teach those poopy heads anyway.
Howard: FYI, I think that's what Darth Vader said just before he started building the Death Star.

Raj: Dance number aside, I'm so not gay.

Penny: Mrs. Cooper? Hey, it's Penny. I think I broke your son. Hold on. Talk to your mother.
Sheldon: (Crying) Mommy, I love you. Don't let Spock take me to the future!