Here's a short list of some of our favorite "off the beaten path" movies (be it that they are older, or just not heavily marketed).  A lot of these movies are timeless classics that my family has been enjoying over and over.  

Charlotte's Web - Sweetest little movie.  Old fashioned animation that deals with the topic of loss in the loveliest of ways. 
The Iron Giant - Great animated film by Brad Bird (The Incredibles and Ratatouille).  Wonderful message of trust, friendship & sacrifice.  Voices of Harry Connick & Jennifer Aniston.  Great film.
My Neighbor Totoro - Anime film by Hayo Miyazaki.  One of the most delightful and charming family films ever.  My 6 year old & I watch this over & over.  Follow the adventures of Satsuki and her four-year-old sister Mei when they move into a new home in the countryside. To their delight, they discover that their new neighbor is a mysterious forest spirit called Totoro, who can be seen only through the eyes of a child.
Nausicaa:  Valley of the Wind - This is another my Miyazaki.  Deals with more mature issues and the importance of taking care of the earth.  It has a heavy ecological message and the story is deep, rich, emotional, and satisfying.  My 6 year old daughter really enjoyed this one, but it is probably better suited for a little bit older audience.
Chitty Chitty Bang Bang - This is a live action film starring Dick Van Dyke and it is long enough to have an intermission.  My kids love it though.
Mary Poppins - Need I say more?  I watched this over and over as a kid and loved playing the soundtrack on my record player. 
Tarzan - This one sat on the shelf for years and I finally pulled it off and we all really loved it. 
Robin Hood - Good old fashioned animation from Disney.  My kids watch this over and over and they laugh out loud.
The Sound of Music - Another classic that you can watch over and over and just love it all the more.  Great music and a wonderful story.
Mulan - Not your average princess movie.  Engaging storyline and good music. 
Peter Pan - Pure old fashioned fun & fantasy and one of my favorites from Disney. 
Pinnochio - This classic is about the magical power of believing in your dreams and also will teach children to be moral and choose the good in life. Terrific message and a true masterpiece of animation.  Lots of subtle and intelligent humor as well.