In Bruges features a great screenplay. The darkness of the comedy doesn't quite come close to 'Snatch' or 'After Hours', but to be able to compare with those two gems itself is a testament.
I'll borrow the services of IMDb's memorable quotes for this movie to relive the pleasure of the dialogues:
Ray: Murder, father.
Priest: Why did you murder someone, Raymond?
Ray: For money, father.
Priest: For money? You murdered someone for money?
Ray: Yes, father. Not out of anger. Not out of nothing. For money.
Priest: Who did you murder for money, Raymond?
Ray: You, father.
Priest: I'm sorry?
Ray: I said you, father. What are you, deaf?
I've heard such lines in other movies before, but the 'What are you, deaf?' is a part of characterization. Ray, brilliantly played by Colin Farrell, is doing his first job as a hitman and he's annoyed at having to answer him victim twice.
Here's another scene, this time Harry (Ralph Fiennes) and Ray are in a shootout and there's a pregnant woman in their middle. Now, since they both are men of principle, they wouldn't want to shock or harm her in any way. This is what they exchange
Ray: Harry, I've got an idea.
Ray: My room faces out the canal, right? I'm going to go back to me room, jump into the canal, see if I can swim to the other side and escape.
Harry: All right.
Ray: If you go outside around the corner, you can shoot at me from there and try to get me. That way we'll leave this lady and her baby out of the whole entire thing.
Harry: You completely promise to jump into the canal? I don't want to run out there, come back in ten minutes, and find you fucking hiding in a cupboard.
Ray: I completely promise, Harry. I'm not going to risk having another little kid dying on me.
Harry: So, hang on - I go outside and I go which way? Right or left?
Ray: [upset] You go right, don't you? You can see it from the doorway! It's a big fucking canal!
Harry: All right. Jesus. I only just got here, haven't I? Okay, on the count of one, two, three, go. Okay?
Ray: What? Who says one, two, three?
Harry: Well you say it.
Oh, it's brilliantly black.