Sight & Sound is the best out there. Unless you want less film theory concentrated reviews then go for one of the others mentioned. Little White Lies is a gorgeous independent film magazine.
Empire and Total Film are the best two - both have websites so you can see the contents for free... Or if you're set on getting them buy a subsciption, works out much cheaper in the long run
I used to subscribe to both Empire and Total Film (both were great in their time). Now I just read the reviews I want online. Total Film was the better mag, imo.