Well I don't subscribe to any at the moment, seems a little silly to me when I could read them at Chapters or the Library. In the past I've had subscriptions to scouting publications and computer sound engineering mags.
But the ones that interest me include a lot of the aforementioned ones like...
Walrus
New Yorker
Popular Science
Popular Mechanics
Time
Scientific American
Discover
Adbusters
National Geographic
People (provides some good pop culture topics)
New York Times Magazine
Nature
Don't read any of them as much as I'd like, but I'm currently on a kick to read more so we'll see how that goes. It's more of a list of what would I read if I read more magazines
Into science stuff, political stuff, current events, etc.
Interesting thread so far, lot's of good ideas.