Howard: So I have a dominant personality. We all know that.
Bernadette: I'm sorry. What do we know?
Howard: In social groupings, I just naturally wind up in charge.
Bernadette: Don't take this the wrong way, but how many of these little booze balls have you had?

Howard: I'm sorry I didn't take you to the airport. I just want you to know I'll never forgive myself for being so selfish. And I promise to keep you close for the rest of my life.
Bernadette: Oh, no, that thing's gonna end up in my bedroom.

Bernadette: (Shouting from the bathroom) How many times do I have to tell you to replace the toilet paper when it's empty?
Howard: I'm in the middle of something.
Bernadette: So am I!

Bernadette: Gosh, Amy. I'm sensing a little hostility. Is it maybe because like Sheldon's work, your sex life is also theoretical?

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.