These are all excellent films so it was hard. I picked Pulp Fiction simply because it has a great mix of comedy, drama, and intense brutality which is necessary for a good gangster film.  Christohper Walken’s cameo also helped. His delivery of that speech is the funniest I’ve ever heard, it doesn’t hurt he was telling it to a kid either.

The Godfather Pt 1
Mafia boss’ innocent son gets involved in the bloody family business when his father is critically wounded in a mob hit.

Starring:
Marlon Brando ....  Don Vito Corleone
Al Pacino ....  Michael Corleone
James Caan ....  Sonny Corleone
Richard S. Castellano ....  Clemenza (as Richard Castellano)
Robert Duvall ....  Tom Hagen
Diane Keaton ....  Kay Adams
Abe Vigoda ....  Sal Tessio

Reservoir Dogs

They were perfect strangers, assembled to pull off the perfect crime. Their simple robbery explodes into a bloody ambush, and the ruthless killers realise one of them is a police informer. But which one?

Harvey Keitel ....  Mr. White/Larry Dimmick
Tim Roth ....  Mr. Orange/Freddy Newandyke
Michael Madsen ....  Mr. Blonde/Vic Vega
Steve Buscemi ....  Mr. Pink
Chris Penn ....  Nice Guy Eddie Cabot
Lawrence Tierney ....  Joe Cabot
Quentin Tarantino ....  Mr. Brown

Pulp Fiction

The stories of two mob hit men, a boxer and a pair of diner bandits intertwine in four tales of violence and redemption.

Starring:
John Travolta ....  Vincent Vega
Samuel L. Jackson ....  Jules Winnfield
Phil LaMarr ....  Marvin
Burr Steers ....  Roger
Bruce Willis ....  Butch Coolidge
Ving Rhames ....  Marsellus Wallace
Rosanna Arquette ....  Jody
Uma Thurman ....  Mia Wallace

The Usual Suspects

villains in New York are rounded up by police in an unconventional manner that worries them. After release, they get together for a spot of revenge, but someone else is controling events.

Starring:
Stephen Baldwin ....  Michael McManus
Gabriel Byrne ....  Dean Keaton
Benicio Del Toro ....  Fred Fenster
Kevin Pollak ....  Todd Hockney
Kevin Spacey ....  Roger ‘Verbal’ Kint

Goodfellas

Henry Hill and his friends work their way up through the mob hierarchy.

Starring:
Robert De Niro ....  Jimmy Conway
Ray Liotta ....  Henry Hill
Joe Pesci ....  Tommy DeVito
Lorraine Bracco ....  Karen Hill
Paul Sorvino ....  Paul Cicero

Scarface

In 1980 Miami, a determined Cuban immigrant takes over a drug empire while succumbing to greed

Starring:
Al Pacino ....  Antonio ‘Tony’ Montana
Steven Bauer ....  Manolo Ray
Michelle Pfeiffer ....  Elvira Hancock Montana
Mary Elizabeth Mastrantonio ....  Gina Montana
Robert Loggia ....  Frank Lopez
Miriam Colon ....  Mama Montana

This was the toughest one so far for me…but The Usual Suspects came out on top. I just LOVE movies that keep me guessing until the end, and then blow away anything I was thinking. When movies like this, or the Sixth Sense do that, I am a happy movie goer.

GoodFellas.  Deniro was his usual great self, and Pesci was just sick.  Classic stuff like: “Am I a clown?  Do I amuse you?  Do I make you laugh?”  Scary ****.

Goodfellas was another great one…but I cant rate it above The Usual Suspects, only because there were a few slow spots in the movie.

Pulp Fiction doesn’t belong in a Gangsters and Mobsters poll and I also question the placement of Reservoir dogs and Usual Suspects in these categories, They are all great movies that I own but this poll is messed up
Casino should be on the list and how on earth is Godfather pt.II up there
Untouchables and Donnie Brasco are others that fit this category