As a product reviewer, I have flown most of today's popular simulators. While none of them are perfect, they are all (At least the high-end sims) as close to the real thing as you can get.

The bottom line is, it really doesn't matter which one you get as far as the actual flying goes, I would choose on the grounds of features that I want (Type of planes, flying sites, views, on-line play, etc)