Penny: Wow, Sheldon, I can not believe you made up your own game.
Sheldon Cooper: Oh, "Research Lab" is more than a game. Like the slogan says, "the physics is theoretical, but the fun is real."
Leonard Hofstadter: We must not be playing it right.
Sheldon Cooper: Stop it, both of you! All this fighting, I might as well be back with my parents! "Damn it, George, I told you if you didn't quit drinking I'd leave you!" "Well, I guess that makes you a liar, 'cause I'm drunk as hell and you're still here!" "Stop yelling, you're making Sheldon cry!" "I'll tell you what's making Sheldon cry: that I let you name him Sheldon!"
Penny: Here, what's going on?
Leonard Hofstadter: It's a little hard to explain. He does this thing where he pretends he's in an alternate dimension that occupies the same physical space we're in, but he can't perceive us.
Sheldon Cooper: Don't flatter yourself; I'm just ignoring you.
Leonard Hofstadter: Hey.
Leonard Hofstadter: We're, uh, going to the movies.
Sheldon Cooper: No, we're not. We're standing in the hallway, suffering through an awkward encounter.
Penny: How 'bout we buy you this robot, and then we all go home.
Sheldon Cooper: I want that one.
Penny: Okay, you can have that one.
Leonard Hofstadter: Oh, come on! He's just going to play with it twice, and it'll end up in his closet with all the other junk.
Penny: Buy him the robot, Leonard.
Sheldon Cooper: Can I get this comic book too?
Penny: Yes, you can.
Sheldon Cooper: Leonard, when that woman moved in three years ago, I told you not to talk to her, and now look, we're going to be late for the movies.
Penny: I hear you don't like my stuffed animals, my driving or my punctuality.
Leonard Hofstadter: What? Who would tell you something like that?
[immediately looking at Sheldon]
Leonard Hofstadter: Why would you tell her something like that?
Leonard Hofstadter: Let me ask you something: do you think it's okay for Penny to have an ex-boyfriend sleep on her couch?
Howard Wolowitz: No, I mean she's obviously way out of line...
Leonard Hofstadter: Thank you.
Howard Wolowitz: But if she dumps you, she'll have a new boyfriend by tomorrow morning, and you'll have a new girlfriend when you figure out how to build one.
Stuart: I was thinking of closing early and going home but, let's face it, that's just a smaller lonely room filled with comic books.
Penny: [to departing customers] Oh, thank you very much. Come back soon!
Penny: With the other half of my tip.