Objects in Space Episode:
Jayne: You sayin' she's a witch?!
Wash: Yes, Jayne, she has had congress with the beast.
Jayne: She's in congress?!
Wash: How did your brain grasp the human language? Seriously, I'm curious to know.
Safe Episode:
"dear diary, today i was pompous and my sister was crazy. today we were kidnapped by hill-folk never to be seen again. it was the best day ever!" -Jayne Cobb
Serenity (pilot episode):
Jayne: "Testing, testing. Captain, can you hear me?"
Mal: "I'm standing right here."
Jayne: "You're coming through good and loud."
Mal: " 'Cause I'm standing right here."
Heart of Gold:
Jayne: (calls out from across the room while hanging all over a whore) "Can I start gettin' sexed already?"
Mal: "Well, that was kind of horrific."
Our Mrs. Reynolds:
Bandit: You gonna give us what's due us. And every damn thing else on that boat. And I think maybe you gonna give me a little one-on-one time with the missus.
Jayne: Oh, I think you might wanna reconsider that last part. See, I married me a powerful ugly creature.
[The "woman" looks up ? it's Mal in a dress.]
Mal: How can you say that? How can you shame me in front of new people?
Jayne: If I could make you prettier I would!
Mal: You are not the man I met a year ago!
I'd go on, but, then I'd just end up quoting the whole series.