Mafia and Hollywood

The Godfather, Scarface, Good Fellas, Casino, etc. for some people the best movies ever made.

what's your opinion? why're these films so famous? waht do you like of them?

Because it gives us insight of what we (or most of us) don't have experience with. Plain and simple.

First cycle was popular for many reasons, although one of the more concrete ideas is that the "bad men" got their just deserts.

Also, when done correctly villains that people will root for.