Flight Simulator X

FilePlanet
Game clients and a demo.
http://www.fileplanet.com/105349/0/section/Microsoft-Flight-Simulator-X

FS Multiplayer
Flight Simulator community dedicated to having fun and flying together. ATC School, flight training, forum and regular flying events.
http://www.fs-mp.com/

FSplanet
A daily assortment of the newest commercial and freeware add-on files for MSFSX. Downloads are rated and described in detail.
http://www.fsplanet.com/

GameSpy: Flight Simulator X
News, previews, and screenshots.
http://pc.gamespy.com/pc/flight-simulator-x/

GameZone
Preview, news, screenshots, and downloads.
http://pc.gamezone.com/gamesell/p28571.htm

IGN: Flight Simulator X
Preview, news, screenshots, and a message board.
http://pc.ign.com/objects/792/792287.html

VA Financials
A free flight simulator addon for virtual airlines to manage pilot reports, financing and fleet. Downloads, support and contact details.
http://www.vafinancials.com/