Hi Mike,
Wow! This post surprises me!! I've been into this program since the first episode aired here in the States!! Like you said, two guys living on the road, driving a cool car and killing monsters seemed like a fantastic concept. However, nearly no one else I know has ever even heard of the program.
Obviously, the show is into it's 7th season, so someone here in the States is watching it. The best that I can gather is that it's popular with teenage girls, who think Sam and Dean are hotties. I don't know what that says about me, but it goes without saying that I like the show on another level. . .
To me, it's the closest thing to the X-Files (which is sorely missed!). They make the running plot lines work, even though the Angel/Demon thing would seem inevitably cheesy on first glance. And the individual episodes are, indeed, like really good 40-min horror films. But what I might like the most is how they have a great sense of humor about the show and aren't afraid to make fun of themselves! Plus, as opposed to teenage girls digging Sam & Dean, I think they choose some incredibly hot women for the show. The season with Katie Cassidy (David Cassidy of Partridge Family's kid!) is still one of my faves!! She's incredible!! And the psychic girl that appears now and then (that had her eyes burned out) is pretty rockin' as well!!
Furthermore, I've tried to get a few of my Psychotronic/Horror friends into the show. While none of them watch it on a regular basis, when they do catch an episode they have been remarkably impressed with how accurate/true the show is to traditional myths and folklore. They've commented, "I was like, how do they know that?!" As if they are the only geeks into that sort of stuff!!
Point is: The show is well done! And I'm not embarrassed to admit I'm a fan. . . Well, maybe a little. . .
Jeff