While not SyFy shows - I'm pretty sure both Reapers and Smallville were filmed there, too.
I know
Supernatural is/was they've mentioned it before on the DVD extra's (both the leads are from Texas though), plus they scored Tricia Helfer as a guest star for one episode when she had some time free from
Battlestar Galactica.
Sam Witwer is actually from the Chicago area, besides the vampire on
Being Human he's also had recurring characters on
Battlestar Galactica and
Smallville, also filmed around Vancouver.
Both
Smallville's Kristen Kruek and
Battlestar Galactica's Grace Park (also
Hawaii 5-0) is from Vancouver though, plus they both starred in
Edgemont, which from the little I saw appeared to be some kind of
DeGrassi rip-off. Mule might know something about that later show, didn't look like my kind of thing but they aired it in syndication on Chicago's WGN on Sunday mornings. It gave me an extra incentive to get up and go to church was the best thing I could say about
Edgemont.