Dunno about a full list Maurice - there's all the usuals, Godfather, Goodfellas, Long Good Friday, The Public Enemy, but what about these:

Kiss Of Death - with Victor Mature trying to go straight and Richard Widmark's debut as giggling psycho Tommy Udo. I love this film.

Brighton Rock - course they're gangsters, they're just a bit down on their luck is all

Sexy Beast - if it didn't have that opening scene with Ray Winstone putting a flannel on his dangly bits, would they have needed a different title?

City Of God - teen gangs in Rio. If you get the chance to see this on DVD, check out the accompanying documentary - it's exactly the same story, but for real

The Wire - okay so it's not a film, but it's pretty flipping brilliant depiction of modern gangsters in Baltimore

Oh you have to see the Long Good Friday - Bob Hoskins in career-defining form (and see if you can spot Pierce Brosnan as the gay-acting hitman).

 The Public Enemy is the Jimmy Cagney one - the final scene will stay with you forever.

I'm on the fourth season of The Wire on FX (cable channel) and it just gets better and better. I believe the fifth and final season has been shown (though possibly only in the US) and I'm expecting to see it from next month.

The Lucky Luciano film I vaguely remember seeing from years ago is called, funnily enough, Lucky Luciano. It's quite dry and matter of fact as I recall, though it's supposed to be historically accurate, showing the links the Sicilian Mafia formed with the occupying US army after WWII.

The Departed

Lock Stock and 2 Smoking Barrels

Snatch

A Bronx Tale (seems to be hardly known by anyone but its a FANTASTIC film that was Robert De Niros first go at directing)

Casino

Reservoir Dogs (Which Tarantino robbed by the way) ~ awesome

Pulp Fiction ~ My ALL TIME fave film

Im sure theres tons of others. Ill have to have a think..............