I selected "other" since my answer is both, it really depends on the situation.
For hiking and navigating from point a to point b utm is my preference since it relates to understandable, consistent units (meters).
However, for global placement, Lat/Lon is much easier to relate to in human terms. I know what latitude certain borders are, and about where certain longitudes place me.
For astronomy Lat/Lon is the gold standard. There is no UTM version for Right Ascension/ Declination. You travel 15 degrees in one hour due to Earth's rotation no matter what your Latitude. Latitude realates directly to the ability to determine what objects are in the sky sometime during the day.
Tony