From what I have heard - Realflight is supposed to be the best one out there. It comes with a controller with a USB port so you can practice with a radio just like the real thing. There is a demo for free located here. But, of course you are using the keyboard for the demo, but at least you can check it out for nothing.

The demo works with one helicopter and I think, three airplanes. It might be only two as I mostly play with the heli and can't remember. But basically Realflight is for learning to fly RC stuff. Try it out and pick the heli. ;)

My epinion on fsx and helis
 

I have no experience with the fsx simulator but I can say that after 6 months of 3 hour a day practice with the Real Flight simulator I was able to fly my 500 size collective pitch electric heli with ease and no crashes. The simulator pays for itself just in the number of learning curve crashes you will NOT experience. It also teaches you everything from the basics to full 3D areobatics with a real time computer generated instructor coaching and giving advice while you fly. WELL WORTH IT GUYS. :TU: I have heard the fsx simulator is more real to life as far as the physics of flight are concerned but WOW the cost is real high. :TD:

running version 3 on my samsung nc10 netbook with the atom 260 and intel mobile 945 express video chip fine with the default settings.