One not mentioned here yet, that is better looking then fms and fairly realistic physics, is clearview, it comes with a lot of planes and heli's with a ton of downloadable extras, and lifetime free updates, it will work with your tx if you buy a cord to plug it into the usb. The looks are nowhere near RF but are decent. it is found here http://rcflightsim.com/ here is a pic of it running on my laptop, on the real pc it looks a lot better.