I really like Gamespot because they are always up-to-date on everything related to games. You have to take some of their reviews with a grain of salt though because there are some flaws that pretty much result in a low score, like bugs in the game. It's understandable though, since games really should be released without as many problems as they usually have, but some games are real gems beneath all their flaws.
I think in general, they're pretty accurate with their reviews. Just keep in mind that anything above a 6.5 might be worth looking into.