>>27195854R/S Sugi is the worst, with the exception of Brendan and May. Character designs are bland and so does the eyes and coloring style. Good thing FRLG and Emerald improved the RSE style, and it shows.
Gen V and VI are fine (gen VI even improved the bland Team Aqua and Magma designs, especially the admins), but I can see why some people hate it (mostly due to the infamous Shauna Face™)