Really enjoyed this series and just finished the fourth season which I hard to say was my favorite. It was a bit different than the first 3 seasons with the mix of Purgatory western moments, Casablanca style scenes, Hitchcock's Rear Window-esque apartment shots and an impromptu musical thrown in just for fun. In any other show it wouldn't have worked but the director did an excellent shot of weaving everything together and it just worked magic. The story line was very of the moment and should hopefully wake people up. We loved it and it was a great way to end the series-highly recommend.