I love this show. Great cast, great stories. I have seasons 1 and 2 on DVD--seasons 3 and 4 in my Amazon video library. Video Library is limiting as far as viewing and they may disappear one day. So I have to download them, save them to my hard drive then save them to disc(to save hard drive space) plus I can only play them through the Amazon player. I perfer DVDs. Seems lately, I can only get additional seasons of my favorite American shows from the UK. I have a universal player so It's not a problem. I guess I don't understand why these seasons on DVD are not made available in the US. Thank you Amazon.uk!