The film Goodfellas comes to mind. Henry Hill (Ray Liotta) smashes the preppie punk eleven times in the face with a .38 snubnose for violating Karen.
http://www.youtube.com/watch?v=AI-VY5cC2jk
And of course the Billy Batts beating.
http://www.youtube.com/watch?v=2oP1NMB_I0s
I love how so many of the cast of Goodfellas turned up in The Sopranos.