Before Sunrise and Before Sunset.

This pair of movies from Richard Linklater, follows the love story of Jesse and Celine (Ethan Hawke and Julie Delpy). Before Sunrise introduces them to us as strangers on a train who get off at Vienna. There they amble about and talk. This talk goes from the simple, "What do you like to do?" to questions about art and philosophy. It's this lively banter, and the feeling that so much is at stake to make that night memorable, to live it to it's fullest, that makes it a great movie.
Before Sunset brings us the couple after that fateful meeting in Vienna. Their reunion gives us an older Jesse and Celine, both a bit weary of the world and both have gone through some tough times since their last meeting. Still, that original spark is reignited and we are taken through a walking tour of Paris and a second chance at love.