Cirago Bluetooth 4.0 USB Mini Adapter - BTA8000
There are actually two different versions of this Bluetooth adapter available, one engraved with "A10" and the other lacking any engraving on the adapter itself. Both versions support Bluetooth 4.0 for great speed and performance as well as some of the best range you can find with a maximum range of 82 feet. That lets you use your Bluetooth devices at a much greater distance but potentially opens up your hardware and system to outside attacks, so keep that in mind.
The version of this adapter engraved with "A10" is a better option, with support for versions of Windows from XP to 10 and Mac OS support. The one without an engraving, on the other hand, only works with Windows XP to 8 and has no Mac OS support. You can only tell which version you are getting by looking at the adapter itself and seeing if it has an engraving, so that keeps this from being as reliably excellent a choice as it otherwise would be.