I was wondering who everyone uses?
I used to use the BBC, but they only do the Kermode podcasts these days.
The only other sites that sprint to mind are rotten tomates, total film and empire on line. none particulary float my boat.
I tend to go here as in AV Forums. You get a feel for those who have a similar taste to yourself. It doesn't always work but it's far better than any professional critic site.
Bri
I tend to go on my own opinion BUT I also use various sites to see what the opinion is out there and I use the sites you have mentioned. You could try aintitcool.com they tend to review more genre films but it's a good source.
Metacritic is good. Generally it's always best to read as many reviews as possible (or none at all).
I wouldn't rely on Empire, I've been buying the magazine for over 10 years and I find the review section to be the worst part of the magazine. They're good for news and exclusives though.