Count me in as a flight simulator enthusiast. I've flown with MS FS2004 some, but I spend more time lately with FlightGear: http://www.flightgear.org/
It's a free/open source project that's been been around for over 10 years. It's not (necessarily) aimed at "gamers" but is every bit as good as FS2004, maybe better in some ways. It has been used by aero researchers and builders of "real" flight simulators.
The project has had contributions from many engineers, pilots and enthusiasts... there's always room for more
If you're interested, check out the user documentation: http://www.flightgear.org/docs.html
and the FlightGear wiki: http://wiki.flightgear.org/flightgear_wiki/index.php?title=Main_Page
To get *all* the present aircraft (more than is included in the distro, some not complete, maybe you could help there?): http://18.104.22.168/flightgear/FGaircraft_20060814.zip
To get the FG scenery for the entire world in one BitTorrent gulp (4 DVDs/15 GB worth): http://www.torrentbox.com/torrent_details?id=59050