Originally posted by gbeaton Can you recommend a good review site?
There are no reliable review sites in the sense that you're asking. You also have to consider the source of the product - if it's provided to the reviewer by the manufacturer, it's possible that it's been pre-selected as a good copy. What review sites have the finances to go out and buy dozens of copies of each lens they test at retail, for a truly random sample, so you'll have some idea of what odds you have of getting a decent copy?
On the other hand, I don't put a lot of faith in, for example, amazon average scores for lenses. I don't believe most consumers make any serious attempt to test lenses. But reading the individual reviews can be helpful, since you get a feel for how seriously the user has tested the lens, and what they're comparing it to.