After being slammed with a restrictive NC-17 rating by the mega-dumb ratings board, Blue Valentine won an R rating on appeal without having to cut a scene or lower its sexual temperature. Good news. This wrenching story of a marriage that rides a roller coaster for six tumultuous years is not to be missed. Ryan Gosling and Michelle Williams give two of the most explosive and emotionally naked performances you will see anywhere. Just know you’re in for a workout. Derek Cianfrance (Brother Tied) directs in a storm of feeling, as if the movie was ripped from his insides. Maybe it was. It took the Brooklyn-based filmmaker a dozen years to get his film made. Still, every scene registers poignantly, from the couple’s first wistful dance on the street to a tryst at a raunchy motel that backfires badly. Cianfrance lets us watch what happens to passion over time. Blue Valentine hits hard — no mercy.