The best replacement for genymotion is bluestacks.

The best alternatives to genymotion are rated as following:
★★★★★  bluestacks
★★★★  haxm
★★★  android x86
★★★  windroy
★★  androvm
★  bluestack
★  youwave

Your alternative for genymotion is not listed? Suggest!
Speaking about genymotion, one probably shouldn't forget about xamarin.

Other search terms related to genymotion and their ratings are:
★★★★★ xamarin
★★★★ android studio
★★★ titanium
You have in mind a companion for genymotion and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of genymotion in all years. Click on graph for more.
genymotion
bluestacks
haxm