A few of my faves...
(Saffron kisses Mal)
Mal: Oh.... I'm going to the special hell.
Alliance Captain: Is there any particular reason you don't wish to discuss your marriage?
Zoe: Don't see that it's any of your business, is all. We're very private people.
(cut to Wash)
Wash: The legs. Oh yeah, definitely have to say it was her legs. You can put that down. Her legs, and where her legs meet her back. Actually, that whole area. That, and above it. Have you seen what she wears? Forget about it. Have you ever been with a warrior woman?
Zoe: Sir? I'd like you to take the helm, please. I need this man to tear all my clothes off.
Wash: Work, work, work...
Mal: Now this is all the money Niska gave us in advance. You bring it back to him, tell him the job didn't work out. We're not thieves... well, we are thieves. Point is, we're not takin' what's his. Now, we'll stay out of his way the best we can from here on in. You explain that that's best for everyone, okay?
Crow: Keep the money. Use it to buy a funeral. It doesn't matter where you go, or how far you fly. I will hunt you down, and the last thing you see will be my blade.
Mal: Darn.
(Mal kicks him into the engine intakes. Another henchman is brought forward.)
Mal: Now this is all the money Niska gave us in advance...
Henchman: Oh, I'm good! Best thing for everyone. I'm right there with ya!
Zoe: Preacher, don't the Bible have some pretty specific things to say about killing?
Book: Quite specific. It is, however, somewhat fuzzier on the subject of kneecaps.
Simon: I never... never shot anyone before.
Book: I was there, son. I'm fair sure you haven't shot anyone yet.
Wash: Mmm. Wife soup. I must have done good.
Zoe: Yes, dear. You done good.
Mal: Did you tell her?
Wash: Tell her what?
Mal: Your husband has demanded that we sleep together.
Zoe: Really?
Wash: What? Mal, come on...
Mal: He seems to think it would get all this burning sexual tension out in the open. You know, make a fair fight for your womanly affections.
Wash: No! That was the torture talking... Remember? The torture?
Mal: I know it's a difficult mission, but you and I... have to get it on.
Zoe: I understand. We have no choice. Take me, sir. Take me hard.
Jayne: Now something about that is just downright unsettlin'.
Wash: We'll be in our bunk.
Jayne: Hey! Free soup!