Fly!

"Fly! has all the signs of a 1.0-level product, and while the foundation is there for the Right Stuff in future versions, this initial release doesn't come together as well as its competitors."

"So what's the final call? There's no question that Fly! is the most advanced general aviation sim currently on the market, surpassing even Microsoft's venerable Flight Simulator '98 franchise when it comes to realism and sheer scope. Unfortunately, it'll take at least a Pentium III 500 machine outfitted with at least 128 MBs of RAM, a third-generation graphics accelerator card, and nearly 2 GBs of hard disk space (!) to get it to operate at a satisfactory level."