I prefer my macadamia nuts dry roasted with salt, and my almonds, walnuts, and pecans raw and unsalted. All of these nuts have 2g net carbs per serving and are great snacks in moderation.
Absolute lowest carb, highest fat, nuts in existance. Buttery and delicious too, my personal favorite.
Tied with macadamia nuts for my favorite nut, Marcona almonds are buttery and delicious.