There is no "best" but for most of the use normal use folks, a red dot is used for short-range target acquisition. A 25-yard or 50-yard sight-in is not uncommon. For home defense use we recommend 25 yards, general use at 50 yards, and any other long-range at 100 yards. It should be mentioned that long-range usage with red dot sights can produce lackluster results without magnification.