I made an Android Virtual Device. It runs on the SDK emulator using Intel HAXM. I was able to see it in Visual studio (debug devices drop down list) and debug my applicatio
Similar issue here, I had a series of android emulators setup in Visual Studio 2015 Android Emulator Manager (AVD), but when I tried to run a xamarin.forms sample, none of the emulators I created were showing up in the debug targets drop-down.
What fixed it for me was to set the android project as StartUp Project manually (right-click project > set as startup project)
For some reason (bug/feature?) it doesn't suffice to just change the selected item from Visual Studio menu drop-down 'startup projects'. Hope this helps!