I subscribed to Dragon from around '99 till it ended, and Dungeon for its last two years. WotC's online version is free, yet I've stopped reading it completely at this point.
My interest waned after they stopped having James Jacobs writing the Demonomicon articles. And around that time Gleemax made it virtually impossible to log on to read anything, and the material rapidly became leftovers and advertisement filler promoting 4e, so I didn't really bother anymore.
The articles now seem to actually have some meat on them, and good for them, except I don't have much interest in the mechanics articles since I don't play or run a 4e campaign, and the FR fluff articles have been downright depressing (and let's not talk about the Zhent headless horseman...). The last article I fully read was Rob Schwalb's Yeenoghu piece, but otherwise my interest has waned to the point where they've probably lost me, even if it stays free.