I think the 1969 set is underrated. Seems like 1962, 1965, and 1967 gets most of the sixties love.
The 69 set has the most HoFers. It seems to be criticized for being similar to 68. Valid critique, but it was an improvement over 68. Cool All Star cards and some of the finest World Series cards ever made. High numbers aren't difficult. Anf finally, sunset card of Mantle.