The wall to wall music
A typical Scorsese ploy to add significance to otherwise mundane scenes. I felt like I'd seen this movie before, and I had, in Goodfellas, Casino, Mean Streets, the Departed, even The Color of Money, et al, with their sound tracks of pop tune after pop tune lending significance to the action. It's a tired act by now, and I wish Scorsese would get over it and get back to good movie making.
I'll start with one of my favorite non-gangster Scorese movies: Kundun.