I ordered one of these Vicro Technilogy Ltd. Bluetooth Mini GamePad (PA-BK11) ’s off of Amazon.
It shows up as “Bluetooth Gamepad” in the Bluetooth system preferences panel, with a keyboard icon. I can click “pair,” at which point it asks me to type in a 6 digit number.
Is there a trick to making it pair without entering the requested PIN number? Having no luck Googling this one. There are one or two articles on accomplishing the same in Linux, but nothing for Mac.
The controller is not anything special, but it’s small enough to fit in my kids’ hands when they play Nintendo games, something that none of the other controllers can do even if they do pair correctly.
 I've since tried this with a newer (2014) iMac at work. Though both it and my own computer (2009 model) use Yosemite, the 2014 iMac doesn't require a pin to be typed in. According to Apple.com, my Mac has Bluetooth 2.1.