Game Informer. It's an awesome magazine that covers pretty much every type of game and every platform. Awesome previews, reviews, commentary, interviews, etc. They're quite witty, too.
I used to subscribe to Nintendo Power, but now I am feeling that they are lacking in good material. They seem to be boring me... sometimes seems they are too afraid to take it a step further. I liked them back in the days of when there were forums... I remember I got my artwork in issue #212, haha. They were neat back then, but now... eh, I don't know. I didn't renew my subscription.
I used to have Nintendo Power for the longest time, but my subscription ended a few months ago and I never bothered to renew it because I felt that almost all of their content could be obtained over the internet in larger quantities by better writers. The only thing I really liked was their odd preview of a more obscure game that there wasn't much info about on the internet at the time, like Tales of Grace and The Calling. Also Dementium II if I remember correctly. At least recently.
Lately I've been picking up Game Informer occasionally. I find it has much better content and covers a lot larger variety of games that is good for me since I have moved on from just Nintendo to PC gaming as my primary source of video games. Plus I find it interesting to read about games on the PS3 and 360 as well, just to get more variety. And they seem to have more exclusive previews and better writing. I still haven't got a subscription, but I'm thinking about it.
I've been mainly reading Nintendo Power every now and then, but other than that, I haven't read a lot of other gaming magazines. The main reason is because I mostly play Nintendo-related video games than I do for any other gaming system.
Currently I only subscribe to GameInformer, and that was through Gamestop a couple months ago. Even though the PS3 and Xbox 360 material doesn't really pertain to me much, they still have good material, articles, entertaining ways of writing that I enjoy flipping through. They also have general video game stuff; there was an article the other month about video games being considered art. It was a very thoughtful article that caught my eye.. I'll probably be renewing my subscription when it runs out.
I was considering subscribing to Nintendo Power, but meh.. Not so sure now.