I have both RealFlight and PhoenixRC. For heli training Phoenix feels better to me. Also, you can use your real RC transmitter to run the simulator, in my case I run JR transmitters. The down side is that you can't (shouldn't) run a real transmitter while flying in an airliner. Yes, when plugged into Phoenix the TX circuitry turns off, but I wouldn't want to answer those questions so I use RealFlight and their dummy transmitter for that purpose.

There's something uniquely geeky about flying in a flight simulator while flying on a real plane. Like I said, good conversation starter.