Amy: Is something bothering you?
Sheldon: Howard dressed up as me and imitated me, and everyone laughed.
Amy: Oh. Well, that must have felt terrible.
Sheldon: It did. I never realized my friends viewed me as an object of ridicule.
Amy: Oh, I don't think that's true.
Sheldon: They laughed, Amy. In a derisive way. Not in the instructive way I laugh at them when they're being stupid.

Leonard: Hey, happy Halloween.
Penny: Oh! Trick or treat.
Leonard: No. Sorry, you're not wearing a costume.
Penny: Yeah, I am. I'm a pharmaceutical sales rep.
Leonard: I'm gonna need more.
Penny: Okay, failed actress who traded constant rejection for a Christmas bonus and a dental plan?
Leonard: Go nuts.
Penny: Oh. I will.

Leonard: So, what are you wearing to the party? Sexy cat? Sexy nurse? Sexy zombie?
Penny: Why do girls' costumes have to be sexy but guys' costumes don't?
Leonard: (scoffs) Say that again with this helicopter on my head.
Penny: Very cute.

Leonard: Hey, do you remember what happened at that first Halloween party that you invited me to?
Penny: When I threw up in the pumpkin?
Leonard: More memorable than that.
Penny: Really? That was pretty impressive.
Leonard: We had our first kiss. On this very couch.
Penny: No, no, our first kiss was at your birthday. Remember? I threw you a party, you didn't make it, and I felt bad for you.
Leonard: No, no, it was on Halloween, and you felt bad for me.
Penny: If we're gonna go through every party where I felt bad for you, we're gonna be here awhile.

Penny: You're not mad at me, are you?
Leonard: No. Of course not. No, we just remember different things from that party. I remember falling in love, and you remember vomiting in a pumpkin.
Penny: I was, like, four feet away. People cheered.

Sheldon: Oh, Inspector Gadget. And I want to say Supreme Court Justice Ruth Bader Ginsburg.
Raj: So close. Kooth Bader Ginsburg. The Notorious KBG.
Sheldon: That's very clever.
Raj: [striking a gavel] Sustained.

Leonard: Are you gonna dress in drag in front of your fiancee?
Raj: Yeah. We have no secrets from each other. Well, except for the fact that I crocheted this myself.

Leonard: Oh, my God, you look amazing.
Raj: I find you guilty of murder, because you are killing it.
Howard: (imitating Sheldon) Well, technically, the Supreme Court wouldn't determine a defendant's guilt or innocence in a criminal matter. They could only reverse or revamp a jury's conviction based on a constitutional or statutory issue.

Howard: You're sitting in my spot.
Sheldon: You don't have a spot. What is wrong with you today?
Raj: Maybe he's cranky because he's off his bathroom schedule.

Sheldon: Well, I can understand how that would make someone irritable.
Howard: Interesting fact: "irritable" comes from the Latin, "susceptible to anger."
Sheldon: Just because I used a word doesn't mean I want its etymology.
Howard: Interesting fact: "etymology" comes from the Greek word-

Leonard: Sheldon, he's being you. He's dressed as you for Halloween.
Sheldon: Oh. So you're not laughing at him. You're laughing at me.
Raj: We're not laughing at you. We're laughing with you.
Sheldon: But I'm not laughing.
Raj: Then the first one.

Raj: Hey, did you guys know this year's the 40th anniversary of Halloween?
Sheldon: Oh, nonsense. Halloween traditions of date back to the Celtic festival of Samhain. Although our current Halloween customs come from the evening before All Hallows' Day, All Hallows' Eve. Thus, Halloween.
Raj: I meant the movie Halloween.
Sheldon: Oh. Well, that's not interesting at all.
Leonard: Did you know the Michael Myers mask from the film was actually a Captain Kirk mask turned inside out?
Sheldon: Okay, now it's interesting.

Penny: Bernadette, why don't we get to dress up at work?
Bernadette: We used to, but a couple guys in the infectious disease lab went as zombies and it triggered a quarantine. The CDC was so mad.

Leonard: Hey, if you really want to dress up, we could throw a party.
Penny: Oh, that would be fun. You know, I used to throw Halloween parties all the time when I moved into the building.
Leonard: All the time? I only remember being invited to one.
Penny: Please don't make this awkward for me.

Amy: What are you going as?
Howard: I don't want to ruin the surprise. You'll see it at work. Just a warning: it's pretty scary.
Sheldon: Is it a bird?
Howard: No.
Sheldon: Is it a dog?
Howard: No.
Sheldon: Oh, I think I'll be fine, then.