If you want to fly planes Picasim is a good fit on a Mac. I have been running it for a year or so. You have to install it through Wine since it is a Windows app. I use Playonmac to do the install since it is really just an app to make Wine easier to use. Anyway, once it is installed I open the folder c I open the file for the app, and open app.icf. Then find the lines for SysGlesDirectory, and SysGlesVersion. Change the settings to match the following, and save:
SysGlesDirectory=pvr
SysGlesVersion=1
Once that is done the program works perfectly with a sim cable from a transmitter, or a dedicated USB sim controller. I have used my FlySky Fs-i6 with sim cable, as well as an old Ikarus Aerofly USB Game Commander without any problems.
For Quads I have used FPV Freerider. There is a Mac native version. It seems a bit funky in the way it receives input from controllers, but once it is mapped right the sim is very nice. I should say that there is a quad in PicaSim as well, but there isn't as much variety as in FPV Freerider.
I have been very happy with Picasim, and it is really easy to get working once you know what to do. If you want to try it, and need help let me know, and I will post a thread with screenshots to show the installation step by step. It only takes a few minutes to get it installed and working.