Raj: Exactly what I expected. Two people forcing their ideas on me and only one gentleman who could be bothered to ask me what my thoughts were. You two are out. Congratulations, Leonard, you're on the team.
Leonard: My mommy raised a gentleman.

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: 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.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Sheldon: *singing in the tune of "Eye of the Tiger"* It's the eye of the tiger, it's the ear of the bat. It's the whiskers of a catfish and the walrus--
Howard: Hang on. Not that your song isn't terrible-- it is... but how do you mention bats and leave out sonar?
Sheldon: You didn't let me finish. *singing* And also regarding the bat. It has sonar.

Howard: First take a picture with me.
Bernadette: Why?
Howard: Well, Raj and I always talked about learning how to make cocktails like this together, so I taught myself and I'm putting this on Instagram so he can see it and feel like a turd. Say cheese!

Raj: Okay, so, what it sounds like is, what we want is a device that can deliver a message through not only sight, but other senses, as well.
Leonard: The most basic sense that any space-faring civilization would have to possess is touch.
Raj: Ooh. Ooh, ooh! We could make a video-playing device that simultaneously translates the information into a tactile medium.
Leonard: All we have to do is rig up a 3-D communication system!
Raj: We-we can totally do that!
Leonard: I know!
Raj: This is great!
Leonard: Yeah, you know what else it is?
Raj: What?
Leonard: Exactly what Sheldon and Howard said.
Raj: Well, thank you for peeing in my slippers.