I generally know what games I'll get and what games I won't well before there are any reviews out. I don't think it makes sense to rely on reviews, I wouldn't even advise anyone to rely on my own reviews because no single review is enough to discern a good game from a bad game by.
Generally if I find a title or premise of a game interesting I will follow all the information on the game from it's unveiling. New media, gameplay reveals, interviews and especially previews. Through the months, as more and more information accumulates on said game I'll be able to build my own impressions on it and decide whether to keep tabs on the game or just discard it from my bookmarks because it doesn't fit my interest.
Reviews are generally useful for either impulse buyers or for those who even after following a certain game for months are unsure about their purchase. Then reading reviews may be helpful to decide if the game lives up to certain quality standards of the reviewer (which you may not share) that may help you lean either way.
But if you do rely largely on reviews then never read only one or two reviews only. Ever. Go over to gamerankings.com a week or two after a game has launched and read through several reviews varying from different scores. I advise you read reviews of each "score zone" i.e a few reviews from 90+ and a few from 80+ and a few from underneath that to get an overall sense of what people enjoy and what people complain about.
Still, I recommend anyone serious about games to not base their decisions on reviews, but rather follow those games you're interested in through the months or years it is in development.
