What a great thread- hadn't seen it before! Since a lot of time has passed since some of these posts, I may as well mention that all 3 seasons of Forever Knight have finally now been released! It took awhile to get them out there, but I managed to get ahold of all of them. Awesome series! American Gothic is also out on DVD- I think I got the complete series as a bundle. I remember when rewatching it that there is a lot of discrepancy with the episodes- they aired them out of order, I think, and it's a little difficult to figure out what order to watch them in, as there are a lot of plot inconsistencies if you watch them in the order they put them in. That was a really excellent series, though I agree with those who said it sorta got lost a bit toward the end.
I suppose I'd regard Twilight Zone as my favorite series of all time, even though because of all the airings (often edited and shortened) by the Sci/Fi/SyFy channel, I've gotten a little burned out by it. But there are just SO many classic episodes. All the similar shows- Night Gallery, One Step Beyond, the Outer Limits, even Amazing Stories or Tales From The Crypt, are all ones I love to watch. I also loved Twin Peaks when it was on, and I recently re-watched that whole series- again, it got a little goofy toward the end but wow, what a great show!
Among some horror/sci fi themed shows that have been on more recently, even though it's pretty far away from DS's genre, Battlestar Galactica was probably one of my top shows within the last decade, and I was also a fan of Firefly, Lost of course, and Heroes' first season-- even though it went downhill pretty fast, that first season still was pretty great. There was also a show called The 4400, which is probably more like what Heroes should've been like. This past year, I really enjoyed American Horror Story and look forward to season 2. I watched Grimm a few times but I think it was on at the same time as another show, and I never really got into it. Was the other show Fringe? I adore Fringe and will be sorry to see it end after this coming season. For some reason, I never got into True Blood or the Vampire Diaries- you'd think they'd be right up my alley! Edited to add- believe it or not, I've never watched a single Buffy episode. What an omission! I have season 1 on my Netflix queue, and one of these years, I hope to plow through the entire series.