Supernatural, Season 4

Sam:
Dean, what are you doing? What, are you, are you leaving?

Dean:
You don't need me. You and Ruby go fight demons.

Sam:
Hold on. Dean, come on, man. (Dean punches Sam in the face) You satisfied? (Dean hits him again) I guess not.

Dean:
Do you even know how far off the reservation you've gone? How far from normal? From human?

Sam:
I'm just exorcising demons.

Dean:
With your mind! What else can you do?

Sam:
I can send them back to hell. It only works with demons, and that's it.

Dean:
What else can you do?!

Sam:
I told you!

Dean:
And I have every reason in the world to believe that.

Sam:
Look, I should have said something. I'm sorry, Dean. I am. But try to see the other side here.

Dean:
The other side?

Sam:
I'm pulling demons out of innocent people.

Dean:
Use the knife!

Sam:
The knife kills the victim! What I do, most of them survive! Look, I've saved more people in the last five months than we save in a year.

Dean:
That what Ruby want you to think? Huh? Kind of like the way she tricked you into using your powers? Slippery slope, brother. Just wait and see. Because it's gonna get darker and darker, and God knows where it ends.

Sam:
I'm not gonna let it go too far.

Dean:
It's already gone too far, Sam. If I didn't you know... I would wanna hunt you. And so would other hunters.

Sam:
You were gone. I was here. I had to keep on fighting without you. And what I'm doing... It works.

Dean:
Well, tell me. If it's so terrific... then why'd you lie about it to me? Why did an angel tell me to stop you?

Sam:
What?

Dean:
Cas' said that if I don't stop you, he will. See what that means, Sam? That means that God doesn't want you doing this. So, are you just gonna stand there and tell me everything is all good?