[Switchblade]

Black. It's still very Showa, so you're going to be looking at mostly one-and-done stories about the latest Gorgom plot with the occasional interruption for a major plot development. It does end with a more serialized arc, though, that gets very, very good.

Kotaro is a good lead character, the recurring villains are all great, and the music is some of the best in the entire franchise. Importantly, the production quality is much higher than the older shows, so it doesn't have that really dated look that makes the 70s and early 80s shows a more acquired taste. The action is really good, but do be aware that there are a lot of flashing lights with Black's finishing moves and they will absolutely be a bad time if you're photosensitive.

Black RX is also a good choice, but it starts off a lot sillier and that can be a deal breaker for some people. It gets really good around the late teens, though, and if you're more into Kamen Riders with form changes you might find that more appealing than Black.