I get Game Informer because they come free with the membership at Gamestop. I prefer it over any other gaming mag, aside from PC Gamer, but in the 90's, I must have tried every single one imaginable. I used to like Nintendo Power, Gamepro, and EGM a long time ago... Official Xbox Magazine is pretty bad now that I think about it. The writing quality has improved with gaming mags and sites though. Have you read some of those reviews from the Genesis/SNES era? Holy shit they were bad. Usually I will pick one up if they have an exclusive that is interesting, but I find myself caring less and less about what they care about. Call of Duty: Black Ops 2? Nope. Assassin's Creed 3? Nope. Mass Effect 3? Not even a little bit. Gears of War: Judgment, or whatever the fuck it's called...Stay away from my wallet! NO!
Game Informer does a little better though because they do a section on the last few pages that examines older games, like one was for the Gabriel Knight series, another was about 7th Guest, stuff like that. Plus, they have pretty decent articles that I never see in the other mags, aside from PC Gamer, which seems to be focused towards an older audience. The decline in gaming mags has been brought about by a legion of shit gaming sites. The only difference is we can read the shit sites for free, but we have to be exposed to just as many annoying ads, and even louder fan rants. Not to mention lots of "DORITOS HALO EXTREME XP POINTS" nonsense. How about that awful GameBanshee place?
I get info from numerous places before making my purchase, including but not limited to:
NMA/tO
Various gaming sites. Even the shit ones.
Gaming mags
Word of mouth at Gamestop or other gaming outlets
Customer Reviews on Amazon
Metacritic
This way I can get a clearer picture of what the game might be like. Usually you will hear complaints about technical aspects of the game, like clipping, lag, bugs, etc, and those can't really be debated. The rest you can fit into your existing framework of what you expect out of the game. In order to truly get a sense of what a game entails you must get inside the game itself. You must delve past the hype and fanboy love and find out what the game really is.
Who made this game? Was it a well known studio or are they an unknown? How long was it in development? How many people worked on it? Is it a controversial sequel that strays from the originals roots? Is it a shooter, RPG, platformer, hybrid, etc? Can you beat the game in 6 to 10 hours? Might be a rental instead of a buy. No real replay value after you beat it? That's usually a quick trade in or a pass. Over 60 hours of gameplay? Often a good sign unless it's all the same shit, like Skyrim or Darksiders. Is it linear or nonlinear? Depends on the genre on if that makes or breaks the deal. Is the game an upgrade of an existing game like Ultimate Marvel vs Capcom 3? How much content is new, is it a quick reshell money grab maneuver which Capcom is famous for? In that case it was, but I bought it anyway.
Whether reviews are relevant or important is entirely up to the person and their expectations. I don't read reviews expecting an honest answer to my decision (Yes or no. This game is good.), but I do expect to have a clearer idea of what the game is all about, the overall level of polish, and how many hours I will get out of it. Most of it comes down to opinion and everyone loves to tell people about their opinion. Look at this place for instance.