Kinda predictable when we have novels and films, but why not? 
Another of my top fives:
1. Doctor Who. No other competition needed, this is my one and forever favourite show. In fact, for a few years I wanted to play the Doctor before looking at more realistic ambitions, such as following in the footsteps of Gerald Durrell and Chris Packham rather than David Tennant and Tom Baker.
But when I first saw the show in 2005 on it's return (I did see one older episode and visited Longleat's DW exhibition before then, but this was my first proper taste of the show), I was hooked. I can now proudly call myself a Doctor Who but regardless of old or new.
And technically, and I'll count it's spin-offs, Torchwood and the Sarah Jane Adventures with this ranking.
2. Primeval. Another show about time travel, but with my paleontolgy interest intertwined, as it's prehistoric creatures invading the present in this one!
3. Heroes. Another great supernatural-stuff-in-the-present show, this has some great twists, but you need to watch every episode to keep up!
4. Being Human. A vampire, werewolf and a ghost share a house in Bristol. Nough' said.
5. The Inbetweeners/Peep Show. I count these together cos the comedy is just too great to put one before the other.
Another of my top fives:
1. Doctor Who. No other competition needed, this is my one and forever favourite show. In fact, for a few years I wanted to play the Doctor before looking at more realistic ambitions, such as following in the footsteps of Gerald Durrell and Chris Packham rather than David Tennant and Tom Baker.
2. Primeval. Another show about time travel, but with my paleontolgy interest intertwined, as it's prehistoric creatures invading the present in this one!
3. Heroes. Another great supernatural-stuff-in-the-present show, this has some great twists, but you need to watch every episode to keep up!
4. Being Human. A vampire, werewolf and a ghost share a house in Bristol. Nough' said.
5. The Inbetweeners/Peep Show. I count these together cos the comedy is just too great to put one before the other.