Wow, let's push the rewind button and name some classics that most people haven't seen but are well worth the time to watch.
Citizen Kane
Clockwork Orange
One Flew Over the Cuckoo's Nest
Rocky Horror Picture Show
Deer Hunter
M.A.S.H. (the movie not the show)
In The Heat of the Night (Again the movie not the show)
Cannonball Run (the sequels were garbage)
1984
The Andromeda Strain
Nosferatu (it's a silent horror film but worth the watch if for nothing more than to laugh at the Vampire)
I could go on, I'm a bit of a movie buff, especially the classics and cult films. If you want to know what are consider to be THE greatest films of all time then go hear...
http://www.filmsite.org/momentsindx.html