As mentioned the Dodosim 206 is the best available for FSX in terms of realism.
The Aerosoft Huey X package is a close second. As for it being hard to fly, I have found it fairly easy, at least in terms of the flight model. The Huey is a fairly stable helicopter to begin with. It responds well to control inputs. A lot more docile than some of the zippier choppers going around anyway.
Nemeth comes in third I guess and beyond that there ins't a lot else...
Oh the Schweizer 300CBi is a fair model I guess.
And another I just thought of that is actually quite good... The Lama X package (if you like those older style choppers).
Good luck
