It's an iconic theme. I like "Goodfellas" too. One night my father and I watched "Goodfellas" and after he said he'd really like to watch "The Godfather," totally forgetting that he owned it on DVD, so we made it a double feature.
Seeing the movies back to back was a fascinating experience. I expected "Goodfellas" to be signficantly more violent than "The Godfather," because it was made over 20 years later. Both movies were about equal in terms of violence. The biggest difference was editing. I have this theory that there is editing before MTV, and editing after MTV. "Goodfellas" has more cuts and more rapid editing than "The Godfather."