Top of the list is the Apu Trilogy, Devi, The Middleman, and Charulata.
http://www.nytimes.com/2009/04/10/movies/10ray.html?_r=1&em
These are outstanding prints, restored by the Ivory/Merchant people. Yes, it's possible to get them on DVD, but why miss the glory of it if you have a chance to see them in a real theater.
Enjoy,
Joanna