Gen 1 < Gen 2 < Gen 5 < Gen 3 < Gen 6 = Gen 4 < Gen 7 < Gen 8
Gen 6 and 4 are tied for me. Gen 6 is really where 3d grew the beard so to speak and enhancements on PC and Series X help a ton whereas 4 has aged almost perfectly except in terms of gameplay design decisions that have been moved past.