I voted for Nintendo Power as well simply because for my generation, it was *the* game magazine to read. They gave the most information available at a time when instant gratification via the internet was not yet widely available. This is not to slight the other magazines, really, because I'd like to be able to look back over both company specific and company agnostic magazines to further my knowledge of their histories.
I would *love* to obtain scans of all the "side" stuff like that, like Player's Guides and compilations and such. I have a number of them myself but none of them are in any sort of condition to flip through a lot, let alone scan. Having scans of them to look at without further ruining my physical copies would be great.