To not overwhelm my list of one director, era, style, genre, etc, my personal Top 10 probably breaks down like so:
1) 2001: A Space Odyssey
2) Apocalypse Now
3) Ran (over a handful of other Kurosawa films ... Rashomon, Seven Samurai ...)
4) The Shawshank Redemption
5) Raiders of the Lost Ark
6) Schindler's List
7) Casablanca
8) The Battleship Potemkin
9) Paths of Glory
10) The Apartment
crap ...
10b) Goodfellas
IMHO, Casablanca is grossly underrated by the "younger" generation of movie goers (and I say this at the age of 31 myself), while I feel pretty strongly that Citizen Kane is generally overrated by just about everybody -- not to say that it isn't a great, great film.
The more I think about lists like these, the more I'm convinced that we may have lived in the most influential period in cinema history and not known it ... the 90s. There are
so many movies from 1990-1999 that are worthy and difficult to argue or find fault with when considering among the greatest of all time.