What kind of bourbon is best for making whiskey balls?
Honestly, "whatever you want" is the only answer :)

I have a similar seasonal recipe, and in various years, have tried:


expensive bourbon
cheap bourbon
rum
Drambuie
Kahlua
And so on...


The flavors of your chosen liqueur will be somewhat muted by the chocolate, and so something with the complexity of Drambuie was a bit of a waste. However, ultra-cheap bourbon was a little disappointing, as it provided booziness but not much other taste. Kahlua, Grand Marnier, and similar choices with their own flavor profiles can play very nicely with the chocolate, so it's also OK to get creative.

The best choice is a bourbon (or other) that you might enjoy sipping on its own, ideally one that is already on your shelf (if you don't mind sharing 1/2 cup of it). If you hate a particular liqueur, you won't enjoy this dessert as much! If you don't know much about whiskey or have much interest in it other than as an ingredient, a mid-range price is probably the way to go. Asking the proprietor of a liquor store can often result in a good brand recommendation.