I don't. I've never read a (game) review... I may have cklicked on one or two of them but i never seem to be able to finish reading them... i just find them boring...
Also i've only been on metacritic once or twice and don't know why this site is such a huge deal... but maby that's just because i don't find any use in game reviews.
If i want to know how the game is there is plenty of material there to get a more acurate look than reviews. Demos or walkthroughs for one.
If i'm on the fence about the game i just watch the first few minutes (or hour) of the game off of a walkthrough, you get way more information out of that and most reviewers don't finish the games anyway so i've pretty much seen about as much of the game as them.