If you're not a big drinker, I'd recommend against the Everclear. Sure, it's the highest alcohol-to-weight/volume option, but my friends who drank it SWORE that the effects lingered into the next day's hiking...probably not a happy thing.
If you have a sensitive palate, don't use Gatorade, because you'll notice that odd aftertaste. Ewww.
I would recommend either tequila (lemon/lime Crystal Lite powder as mixer, and if you want to get fancy, add a small amount of Cointreau to the tequila at home) or vodka (orange Crystal Lite). You could also try mixing bourbon with lemonade powder. In all cases, dilute with water as needed.
And, of course, adding any type of whiskey to warm, creamy, sweet coffee surely can't fail to please even a non-booze-loving person... Cheers!