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.