Fireball is good in moderation, I can't drink more than 3-4 shots before my teeth hurt from all of the sugar.
If you're gonna mix whiskey, just get something super cheap, why would you buy expensive liquor to mix with something to destroy the taste? The point of an expensive liquor is that it has a better taste ie fireball is like 18 bucks for a 5th or you could buy two bottles of ten high for the same price...