Tennessee & Wheat Whiskey
The styles that don't get called for by name, yet.
Tennessee sour mash
What sets Tennessee whiskey apart is the Lincoln County process: the spirit is filtered through sugar maple charcoal before it ever reaches oak. The result is lighter than bourbon, sweeter, with a notably long finish. In most other respects it follows bourbon's rules.
Of the two widely available names, George Dickel and Jack Daniel's, Dickel is the more complex and makes the better cocktail, though bourbon and rye remain more versatile, which is why neither shows up often in recipes.
Wheat whiskey
Plenty of bourbons lean heavily on wheat, like Maker's Mark, Old Fitzgerald and Pappy Van Winkle, but a true wheat whiskey needs 51% or more. Only a handful exist, Bernheim being the best known, and the scarcity pushes the price past what most people want to pour into a mixed drink.
It is genuinely tasty in Manhattan-style drinks. Call it a home bar indulgence rather than a workhorse.