Thanks Balthazar, and an interesting point about comedies perhaps being more open to original screenplays than drama.
Interestingly several of the original dramas on your list are (to me) really pastiches of other movie traditions, which may come from literary traditions:
Star Wars is avowedly a distillation of
Flash Gordon/
Buck Rogers cartoons and serials and Asimov's
Foundation Trilogy/
Robots (and
Foundation is acknowledged by Asimov to have been inspired by
Decline and Fall of the Roman Empire);
Indiana Jones makes use of the Lash LaRue Saturday serial format and such, and
E.T. is getting on for
Lassie/
Flika/
Old Yeller...
But as you say, so much of Chaplin, Keaton, L&H, Harold Lloyd, down to the canon of Woody Allen are original (I'm suddenly reminded by a little voice at the back of my head that Keaton made
Seven Chances, a re-make of
Seven Keys to Baldpate, adapted by George "Yankee-Doodle-Boy" M. Cohan from a story by Earl Derr Biggers.
While it isn't original, it may also not be a masterpiece (your criterion above), save that it does have a man being chased by a
huge boulder - did that influence Spielberg too, I wonder?).
I'm also wondering if more films actually come from sources which we now forget; the huge number of outlets for short stories in magazines and dime novels surely drove many films that we don't
think of as adaptations at all - as you say
Some Like it Hot, is an adaptation of
Fanfaren der Liebe, which came from a story.
Casablanca may be the most famous example of this, as it was a huge hit as a film based on a play that failed to find a backer,
Everybody Stops at Rick's.
mct16:
I'm surprised to see criticisms of Alan Moore
Well, I do admire his ability to write, especially in short forms - his
TimeTwisters in
2000AD, for example, and his
For the Man Who Has Everything in
Superman Annual Nº11; however, I'm not at all certain about his longer-format material.
Watchmen (the comic) starts really well, but meanders about ineffectually in places, and the trans-dimensional-psychic-squid-monster ending was just
sooo disappointing at the time. I'm old enough to have been buying it as it came out in issue format, and after waiting so long, through delays and whatnot, it was a
tremendous let down).
League of Extraordinary Gentlemen (again the comic) also suffered from not being as good as it thought it was - other writers have done
far better teams of historical/ fictional characters:
Riverworld did it earlier, and Kim Newman does it much better than anyone else in his
Anno Dracula books.
But I really do respect Mr. Moore for his eloquent advocacy of what comics can do and can be, and for his modest expression of his just trying to do better as he goes along.
My reservations of the book I outline above; the movie, well it perhaps suffers from being almost too slavish a staging of the comic - but in an impressive way, if that isn't too self-contradicting.
It makes as much of an effort to re-stage the look of the book as say
Girl with a Pearl Earring did to recreate Vermeer - which is a lot.
Unfortunately this often results in the three-dimensional actors/characters standing around, in the poses of their two-dimensional originals, delivering the speech bubbles, as it were, without getting a cinematic vernacular of its own going.
Other draw-backs are only average acting, some really poor make-up and wigs (you really can't have a 42 year old man play his character's seventeen year old version and expect it to work, no matter how good an actor), and really ho-hum original soundtrack that so wants to be Vangelis doing
Blade Runner - and isn't (although the stand-out exceptions are the extraordinary, beautiful, opening credit montages set to Bob Dylan's "The Times They are A-Changin'", and the re-working of Dylan's
Desolation Row by My Chemical Romance)...