FE Fates is a mixed bag. Conquest offers more challenge and more mature story. It's probably the best of the three. Birthright allows backtracking and unit grinding, so a lot of the enjoyment there is laxed team building. Revelations is so insanely terrible that it brought down the entire package for me. I enjoyed aspects of Fates, but it's clear why the FE community hold it to so much disdain.