I check the consolidated score of gamerankings and metacritic, if the game is above average (over 7.5) I check always IGN first, I learned that they have almost the same tastes in games as me.

I hate the reviews of Gameinformer.

I mostly look at reviews from Gamespot, Gametrailers, and Giant Bomb.

IGN

I go to GameRankings.com and look at average review score. Then I read one or two of the highest reviews, and then I read one or two of the lowest reviews.

More and more, I've been getting recommendations from members here. They've pointed me to de Blob, No More Heroes, Zack and Wiki, Lostwinds, World of Goo, and Boom Blox. I already know a bunch of stuff I should be looking out for in 2009, as well.

I usually listen to what Yatzee says at Zero Punctuation. His views on good games often match my own.

gametrailers, 1up, ign, vgchartz

Destructoid
GameSpot
IGN (I like how deep some reviews are).

the only one I care about is IGN

The rest don't matter. I don't even use metacritic that much because reviews from no-name sites affect the ratings greatly. I know I'm using Meta right in my sig now, but thats because its easier to find all the ratings then it is on IGN.

I used to read IGN reviews but less so now. They give too high a score for many games. Prince of Persia 9.3 and 9.4? Resistance 2 9.5!?!?? GTAIV 10!!?? MGS4 10!??!? They. Buy. Into. Hype.

Now I just tend to use:
-metacritic
- gamefaqs user reviews (not read them actually but just to scroll down the scores)
- previews/video footage/screenhots --> 'And asking myself would this game appeal to me?'
- I still look at IGN reviews but don't really think "wow it scored 9.5, I must buy this game"

Ign long write up and vid review, individual # mean less.