Q400 SiM
FlyJSim do a Q400 Package for X Plane. I have it. From a professional pilots perspective and someone looking for a plane where I can fly the correct power setting and attitudes, it is rubbish. The PFD does not have half of the available information displayed.
Majestic, at the time of writing, only do the 300 series. Haven't flown it. However they supposedly supply Dash operators so it should be pretty good.
It is a shame PMDG don't do one as I have their B737NGX and the flight model is very accurate.