The BBC original Being Human is quite well done. The SyFy version has its strengths, but I don't think its as good. However, it is improving. The premise is sort of Three's Company for the supernatural set, but more angsty, more subtle, and more of a drama/dark comedy.
Survivors from BBC is very well done, but I don't know if its still in production or if its just in a lull. Its the story of normal people who survive a super-flu.
Another excellent series in the same limbo is the BBC's Apparitions. Its the story of a British Catholic priest/exorcist who has been targeted by Satan.
Primeval is a nice sci-fi action show from the BBC in which two-2ay time portals keep opening at random, allowing critters from the past and future run amok in present-day England. They're not afraid to kill off main characters, which is both a blessing and a curse. It keeps you guessing, for one, but if your fave gets killed off, its a bummer.
I'm still enjoying Dr. Who and Torchwood- again, both BBC shows.
From THIS side of the pond, The Walking Dead is one of the best takes on zombie apocalypse I've ever seen.
Warehouse 13 on SyFy is an amusing comedic sci-fi version of shows like Friday the 13th: the Series.