Kiki's Delivery Service.
Though My Neighbour Totoro and Laputa run a close second. And Spirited Away. Hell, anything directed by Miyazaki really. But Kiki I owned on video tape (fan sub and official release), DVD, and even laserdisc, because I liked it that much.
Other favourite foreign films include Seven Samurai, Metropolis, and M. I only got to see M last year, and it's amazing how fresh it is. Most classic films tend to suffer from everything else on film or TV ripping off every clever bit of business to the point where the original tends to look cliched, but despite how old it is, M has stuff in it that has escaped being copied to death.