Post from Luna:
https://www.nhk.or.jp/anime/kamen-rider/ranking/
NHK did a giant poll with half a million votes ranking best show/movie, best Rider, and best music.
Notable highlights: Den-O basically wins with best show, best Rider and top 5 for music. Build is ranked #5 in show but before that the most recent show is OOO.
Best show/movie only showed the top 25 so Wizard/Saber/Ghost are not ranked. Hibiki just barely squeaked in at #24.
The top 10 of best Rider are all titular Riders EXCEPT for #10, KR Grease. Eternal is incredibly popular for a movie Rider, coming in at #17. Genm actually beat Ex-Aid in popularity, #19 to #29. Despite the actor's super popularity right now, Drive is only #30. Saber hits #58, Ghost #69, Wizard #14.
Music is actually a bit surprising, Excite hits #1 followed by Be the One at #2, and Anything Goes at #3. Top ten are all main themes except P.A.R.T.Y ~Universe Festival~ from the Zi-O movie, Time Judged All (banger) and Elements.
Overall I agree with most of the rankings here so I'm rather hopeful that Toei sees this and makes some decisions accordingly as how to approach Rider from hereon. (Not hiring the Ghost/Saber writer again would be a big step forward)