A difficult question to answer without specifying a genre. I have tried to pick my top eleven list from a wide range of genres, perhaps with an overrepresentation of dramas.
The best of the best? Hmm...I'll have to get back on that one.
Here they are anyway (listed in no particular order):
#
Hana-Bi (by Kitano Takeshi - Drama)
I don't know if this actually categorizes as a drama but to me that's what it is. It's quiet, explosively violent, very Japanese, very beautiful, very cool, and very sad. The main character played by Kitano says almost nothing throughout the film and that's how me and my friends felt when we came out of the cinema - speechless. It's really one of those films you can't discuss, it's simply breathtaking....but another friend hated it, so...
#
Ran (by Kurosawa Akira - Historical Drama)
Violent, epic, beautiful, with fantastic sceneries, costumes and battle scenes. The story is based on Shakespeare's King Lear but carefully reconstructed to fit medieval Japan.
#
Scarface (by Brian de Palma - Gangster Drama)
This is just a cool film in every aspect - the actor (Al Pacino, one of my favourites), the set (70s & 80s Miami), the story (a small hood gangster whose life is teared apart by money, power, drugs, and sex and as he rises to the top he's sinking deeper and deeper, becoming more and more paranoid, and there's only one way it can end). In this category "Goodfellas" by Martin Scorsese and "Once Upon a Time in America" by Sergio Leone come in close too..
#
Apocalypse Now (by Francis Ford Coppola - War Drama)
A partly surrealistic and symbolic film about the confusion, violence, fears, meaninglessness and nightmarish madness of the Vietnam War. There's nothing cool or heroic about it. It's very good... I have plenty of war movies on my list, but if I must pick just one, then this is it...
#
Farewell My Concubine (by Chen Kaige - Drama)
Also very beautiful and epic, taking the viewer through very different and turbulent times in China's history - the end of the imperial dynasty, Chiang Kai-Shek's rule (or is it transcribed as Chen Kai-Shek?), the communist revolution and finally the cultural revolution....and Leslie Cheung is excellent...and Gong Li...ahhh! Yellow Earth is supposed to be very good as well, I suspect that it might even be better (I think it was filmed by Zhang Yimou) but I haven't seen it yet.
#
Raise the Red Lantern (by Zhang Yimou - Drama)
It's difficult to pick one Yimou film, there are at least another two that are almost equally good, e.g. To Live, but....as with all Zhang Yimou films all the scenes are extremely well composed...
#
The Godfather 1&2 (by Francis Ford Coppola - Gangster Drama)
These two are inseparable I think, other than that I just realized there's no way I can write comments to all 10 movies...
#
Citizen Kane (by Orson Welles - Drama)
I think it's been called the world's best movie. You have to see it only for that. Even if it's not number one in my book, it's still very very good.
#
The Third Man (by...ahh I don't know actually, it's quite old, late 1940s I think? - Thriller)
Very suggestive, tense atmosphere. Excellent actors. The ultimate thriller...
#
2001 - A Space Odyssey (by Stanley Kubrick - Science Fiction)
It was one of the first real science fiction films and it set the trend for all others to come. It is a fascinating story and it's got that cool space age design to everything in it. 35 years later the effects still look good.
#
Lord of the Rings (by Peter Jackson - Fairytale)
Tolkien never wanted three books but had to give in to his publisher. In every sense, the trilogy should be seen as one story. Peter Jackson's work is very true to the books, which btw I have read three times. I've obviously only seen the first two films, but they are fantastic in every aspect: the set, the casting, the attention to detail...stunning! No further comments needed: first read then watch.
***
There are at least a dozen or more movies that are just or nearly as good as the above. I might include these later on.
Runners up: A Better Tomorrow 1&2 and a whole bunch of other Hong Kong films, especially those starring Chow Yun Fat, Tony Leung or Maggie Cheung and/or directed by John Woo, Chungking Express or almost anything else by Wong Kar Wai (throw in Maggie Cheung as well and you can't go wrong), Blade Runner, Enter The Dragon, Full Metal Jacket, Monty Python.., Pulp Fiction, Star Wars Episodes 4 and 5, at least a couple of Jackie Chans, Sergio Leone's The Good, The Bad, and The Ugly and Harmonica, Clint Eastwood's Unforgiven, at least three John Huston Westerns, at least one Sam Peckinpah, and too many older French and Italian films to mention or even recall the names of here, etc...
Hmm, must work on my top 50 list.