I don't have a "best". I always visit a bunch and see what they all say

I read reviews made by other gamers from GameFAQs, one 0/10 review and a 10/10 review, that'll give an idea of what works and what doesn't Still, demos are the best way to see if you'll like a game.

I used to use Gamespot exclusively until I realised how biased they were.  Several EA game reviews opened my eyes to how badly they review stuff.  These days to get an unbiased (as I possibly could) review I use a couple of sites like Gamespot and IGN for general info and use Metacritic for an idea of how good it is.

I guess my top three (3) none strat sites would be:

destructoid.com

kotaku.com

videogamer.com

If you are in the UK, a brand new site - with a very cool concept, which I think will become bigtime within the year is: nowgamer.com

I look at Metacritic for the individual review links.  I don't pay much attention to the metascore. 

It's useful to find sites that specialize in the particular game genre, like Tacticular Cancer or Strategy Informer for strategy games. 

Gamespot and IGN are dead to me.  They MUST be getting big payments to lie about the games they review.