Kamen Rider V3, the first of many sequels had it's premiere on February 17, 1973.
thanks to the fine folk at Generation Kikaida you can still get the show with English subtitles and tons of extras.
it's considered by many fans as the best Kamen Rider series. it's hard to argue that. I like it a lot, but it's mainly due to the excellent Hiroshi Miyauchi as Shiro Kazami. he's just amazing in the role.