I also used to subscribe to Nintendo Power back when it was new (I still remember the SMB2 issue fondly). I canceled after two years I think. I subscribed for a year two more times when they had great giveaways:
Free Majora's Mask soundtrack in 2001
Free Legend of Zelda: Collector's Edition for Gamecube in 2003
Now with the whole internet thing I'd have a hard time justifying magazine subscriptions. That doesn't stop the annoying door-to-door magazine guys from ringing my doorbell once a month though