Superior to the rest.
'A cut above' comes from the old practice of baking bread over coals. The bottom of the bread would be charred and not be as desirable as the bread at the top of the loaf. The more privileged members of a family or group would get a cut (slice) of the bread that was above the less-privileged members.
This practice was also the origin of the term 'upper crust', meaning wealthy, since the people with the most money could afford the upper crust of the bread in those days.