For music reviews by seemingly "with it" folks:
allmusic. Music reviews to me are most useful when determining which record of a specific artist to get, not which artist to look up.
I've been reading that site's reviews intensively for many years and have accumulated a huge inventory of print-outs from there also. From time to time I'll go through the print-outs and pick out my "gotta have's" from my "wanna have's" ( or try to, anyway ) and then order them.
It's funny how many reviews ( there and elsewhere ) lately focus more on the lyrics and "themes" of a group than they will focus on the actual style of music ! After reading one of these, I'll be scratching my head thinking "Wait a minute - I still don't know if we're talking dance music, or techno-house, or 'classic rock' ( I don't know why, but I hate that latter term ) or what." Apparently that didn't matter much to the reviewer, but it's pretty important to me. Call me "old fashioned" or something.
I am also sometimes disappointed in reviews that rave about something being the best thing the reviewer has heard in years, when it seems pretty vanilla to me when I go out and buy it/check it out. Then I ( perhaps wrongly ) assume it must have been written by someone much younger than me that doesn't have a much tradition to compare it to.
* remembers hilarious parody of rock album reviews done by the National Lampoon magazine years ago *
Back on topic - I'll read online mags like "Salon" and "Slate" sometimes. For music, I used to read "Wire" at the newsstand. "Wired", mentioned already in this thread ( different from "Wire" ) is still pretty good sometimes, but has slipped in recent years, IMHO. I read "Rolling Stone" as an early 70's university guy, but I think it absolutely sucks now. There's an image oriented magazine that lets you discover new artists and buy direct from them that I like sometimes. I think it's called "Artist Direct" but I'm not sure.