I used RealFlight, it's very good.
Each of the three major commercial sims have some pluses & minuses, overall, I liked RealFlight more and bought it.
They have more planes & copters then the others, unfortunately, not the ones I fly.
Go to the local hpbby store, they should have at least two (of the three) of them up ... try 'em both for a while. Pay attention to the feel of the controller and the graphics ... get the one that looks & feels best to you.
Get one that includes a controller. Trying to fly the real planes/helis after learning from a keyboard, joystick, or game controller won't really help much. Some include a cable that allows you to use your actual transmitter ... if ou have ne, that's a good way to go (though, I believe all of them allow ou to interface your real transmitter through the included controller).
I can say *for a fact* (since I am now flying/crashing real helis ... even if the "cheap" ones) that the $200 for the sim has probably saved me thousands in parts and repair time (not to mention the frustration of the fly/crash/fix cycle).
Good luck
Scott