There are really so many different types of art, be them paintings, music fashion,whatever. Films can also be art, simply because of color and music and costume, and i believe movies have ceased to be art because of the way they are made, and the color used.
Movies from the 1970's are the best kind,using bright,vibrant colors. One of my favorite movies, Suspiria, uses 3-strip technicolor and spooky, whispery music to make it feel like a dream, yet still be terifying. The main theme of the soundtrack is in the entry right under this one.
Suspiria is a movie that everyone should see, because it's beautiful and vibrant and art.
Texas Chainsaw Massacre was art as well, simply because it was shot in normal weather and not through a 'bruisecam'.
You don't find movie art much anymore because that's the way (mostly horror) movies are shot. They are no longer vibrant art-in-motion but dreary stories that make you more depressed than scared. (kind of like how Michael Bay ruined TCM, and more recently has ruined Nitemare on Elm Street >.<)
I think there should be a revoloution in film making, and we should try to achieve that vibrancy again, and turn movies back into art.