Android Studio and its accompanying emulator have actually improved considerably. I'd even say the emulator that ships now is perfectly sufficient to use, although there's obviously the better alternative(s) like GenyMotion.
Having said that, the Xamarin Android Player is probably the best out there for a free fast booting emulator.
First install the XAP, no need to install Xamarin Studio.
Launch Android Studio, have your project ready to launch on an emulator.
Here's thing, the running XAP (after you create a device and press play) will not show up in Android Studios list of devices in the AVD. Don't fret, as it won't matter.
When you finally push the run button you will get a screen like this with an option to now launch on the XAP:
Now you can use the XAP for your project :)