S01E06
-Penny: Hey, I'm having a party on Saturday, so if you guys are around, you should come on by.
-Leonard: A party?
-Penny: Yeah.
-Howard: A. "boy-girl" party?
-Penny: Well, there will be boys and there will be girls and it is a party, so...It'll be a bunch of my friends. We'll have some beer, do a little dancing...
-Sheldon: Dancing?
-Leonard: Yeah, I don't know, Penny...
-Sheldon: The thing is, we're not...
-Leonard: No, we're really more of a... No. But thanks. Thanks for thinking of us.
-Penny: Are you sure? Come on, it's Halloween.
-Sheldon: A Halloween party?
-Howard: As in... costumes?
-Penny: Well, yeah.
-Leonard: Is there a theme?
-Penny: Uh... Yeah, Halloween.
-Sheldon: Yes, but are the costumes random, or genre-specific?
-Penny: As usual, I'm not following.
-Leonard: He's asking if we can come as anyone from science fiction, fantasy...
-Penny: Sure.
-Sheldon: What about comic books?
-Penny: Fine.
-Sheldon: Anime?
-Penny: of course.
-Sheldon: TV, film, D&D, manga, Greek gods, Roman gods, Norse gods...
-Penny: Anything you want! Okay? Any costume you want. Bye.