I wouldn't put Garo's action anywhere near the top. It was brisk, sure, with a level of martial artistry and athleticism that's uncommon for the genre, but that largely only encompasses the untransformed fights--the rest were bland, underthought and overdone FX spectacles that I mostly fast-forwarded through. I think people are sometimes distracted by the flashy wushu maneuvers and intracy of some of the exchanges to the point where they don't realize that a lot of the action scenes in Garo, despite chiefly being somber and gloomy affairs, lacked real impact and therefore substance, and all the acrobatics and posing then just felt frivolous.
For my personal tastes (being a martial artist and action film zealot who was raised on kung fu movies, which lends me at least some credibility), I've most enjoyed the action setpieces in shows like Denjiman, Bioranger, Dairanger, KR Super One, KR Black, KR Agito (how do people forget about this one?), KR Kabuto, Justiriser, etc. This excludes a lot of shows that people normally mention and features some that are all but forgotten, primarily because there's an unfortunate pattern of shows with otherwise solid action direction being hampered by a profusion of cheap special attacks and an overreliance on visual effects. Otherwise, Kakuranger, Gaoranger, Gekiranger, and Double would have made the list.
