I am going to go for the less quoted quotes among their great quotes. We all know about "I hate rudeness in a man" etc.
Here's a few:
Newt: Gus, are you sure the Captain is my father?
Gus McCrae: Yep, he is.
Newt: He ain't never mentioned it.
Gus McCrae: Well, Woodrow ain't much of a mentioner.
Gus McCrae: I've got to go after Blue Duck. I expect he's up on the Canadian somewhere. If I could trouble you for the loan of a horse, I'll return it and probably a few more.
Gus McCrae : You don't get the point, do you Pea? I mean chase 'em, because before long, there won't be any buffalo left TO chase
Pea Eye Parker : Them bulls 'll hook you. D'you remember ol' man Barlow? A buffalo hooked him bad
Gus McCrae : Old man Barlow was a slow thinker, kinda like somebody else I could name
Pea Eye Parker : Well he was a slow walker, too, after that buffalo got through with him.
Pea Eye Parker : What Indians is it we're fightin' anyway?
Augustus 'Gus' McCrae : They didn't introduce themselves.
Jake Spoon: "Hey, didn't Deets have that same cap before I left?"
Augustus 'Gus' McCrae : "Well, you know Deets. He ain't one to quit on a garment, just 'cause it's got a little age."