S1, Something Wicked
Sam: Dude! I can't use this badge!
Dean: Why not?
Sam: It says 'bikini inspector' on it!
Phantom Traveler
Sam: Are you humming Metallica?
Dean: Calms me down.
Dean: Dude, stow the touchy-feely, self-help-yoga crap. It's not helping!
Wendigo
Dean: Oh sweetheart, I don't do shorts
Dean: Yeah, you want some white meat, bitch? I'm right here!
Haley: Must you cheapen the moment?
Dean: Yeah!
3x14
Sam: It's a Crocotta.
Dean: What's that? Some kind of sandwich?
3x08:Dean: What'd Bobby say?
Sam: Uh, that we're morons.
3x13
Dean: There's a box of salt in my duffel. Make a circle and get inside.
Ed Zeddmore: Get inside your duffel?
Dean: The salt, you idiots!
S3 3x6 Bela: Come on! You do this out of vengeance and obsession. You're a stone's throw from being a serial killer.
S3, Maleus Malificarum
Dean: What was that stuff? God, it was ass. Tasted like ass.
Ruby: It's called witchcraft, short bus.
Dean: You're the short bus, short bus.
3x12
Dean: This is pretty wild, right? I mean it's like they're coming straight for us. They've never done that before. Like we've got a contract on us. You think it's 'cause we're so awesome? I think it's 'cause we're so awesome.
...
Ruby: Does anyone have a breath mint? Some guts splattered into my mouth while I was killing my way in here.
...
FBI Agent Henricksen: Sam and Dean Winchester were in the chopper when it caught on fire. Nothing's left. Can't even identify 'em with dental records. Rest in peace, guys.
S1, Hell House
Sam: I was the one that called them and told them I was a Hollywood producer.
Dean: Well I was the one that put the dead fish in their back seat.
Probably too long.
S2 2x13 Sam: I don’t know, Dean, I just, uh, I wanted to believe so badly. It’s so damned hard to do this, what we do. All alone, you know. And…there’s so much evil out in the world, Dean, I feel like I could drown in it. And when I think about my destiny, when I think about how I could end up…
Dean: Yeah, well, don’t worry about that, all right? I’m watching out for you.
Sam: Yeah, I know you are. But you’re just one person, Dean. And I needed to think that there was something else watching too, you know? Some higher power, some greater good. And that maybe I…
Dean: Maybe what?
Sam: Maybe I could be saved.
3x10
Dean: He's the one who let mom die! Who wasn't there for Sam, I always was! It wasn't fair! I didn't deserve what he put on me and I don't deserve to go to Hell!