Absolutely. The first 5 seasons of Supernatural are excellent. It builds to a crescendo that is a really great end. The following 10 seasons have their ups and downs, but I think that it is pretty good overall.
Jensen Ackles and Jared Padalecki both did an amazing job as Dean and Sam. Their chemistry together is what makes this show so special. Like any great show some seasons were better than others but even the lesser ones are still worth watching. The only real negative about this show is the ending.