Hi,
the best simulator I have ever seen is [link=http://www.rc-sim.de/art_engine/article.php?article=64]this one[/link].

It has really outstanding graphics and an unbelievable physics model. I would say: better than G3, Reflex, AFPD and PhoenixRC together! Really!!
But please - be aware that it has a compatibility mode. If you PC is too slow it switches to a low graphics mode with really poor details.
So don't wonder if you see only a flat scenery with low detailed models. Then your PC is not good enough.

Cheers,
Lego