I guess I can only tell you what I use the most. I am not a report-centric person. I filter most datasets I want on-screen using the index filter - and upload my tree to WorldConnect where people can find a pedigree, descendant outline, descendant register and ahanentafel - which are all basic type reports.
I have custom reports for
cemeteries in a county and
veterans (by war, by line, etc)
veterans who died in service of their country (again, by war or ancestral line, etc.)
"saved" ahnentafels for my grandparents and/or great-grandparents. Alph
Alphabetical listing of descendants of various grandparents or higher level ancestors.
All the presidents in my file - all of the New England presidents
Top-of line ancestors
Dead ends - ancestors I have reached the proverbial brick wall.
and probably more that I can't think of right now.