Rcforum.co.za

FREE

Helisim: http://www.marksfiles.net/HeliSimRC/index.htm
FMS: http://www.flying-model-simulator.com/
Heli-x: http://www.heli-x.info

BUDGET:

Clearview: http://rcflightsim.com/

Realflight : http://www.realflight.com/new/index.html

Very cool site once you have Realflight
http://knifeedge.com/forums/downloads.php

This site has many Aircraft, Aircraft Color Schemes, Airports and Recordings for RealFlight that you can download.