Lucky Number Slevin (2006).
A rewatch for me because I spontaneously remembered seeing it and enjoying it and wanting to watch it again.
In a city there are two mob bosses. They used to be friends and now they are not: now they live in hostile paranoid truce. Until the son of The Boss is killed, and then he wishes to even the matter with The Rabbi. Little do either of them know that there are some other people in town who may interfere with their plans.
I still like this movie. I also like the wallpaper in this movie. You have to watch it to find out what I mean!