I don't believe a film has caught me this off guard in quite some time. I didn't know much about it going in and definitely wasn't expecting the emotional impact that the film brought. River Phoenix gives another wonderful performance, showing again just how great he was at such a young age. And Lumet continues to surprise me with his versatility as a director and his ability to get the most out of actors. If you haven't seen or heard of Running on Empty I'd suggest you seek it out, it really is quite great.
Side note: The Fire and Rain scene was really sweet and got me rather emotional. I think hearing James Taylor sing as River Phoenix danced was heart wrenching (in the best way) for some reason.