Extremely varied so there will always be something for anyone
And most importantly, extremely earnest about itself.
It's people in rubber suits and shoestring TV show special effects. On the surface it's silly, but it takes itself and the story its telling so seriously that it drags you in and you take it seriously too and it becomes unironically cool. Seriously, I think that live action adaptations of anime should go the Tokusatsu route for their fight choreography, they have stylish live action fights down to a science.
Plus unlike the West's attempts at adapting Toku (Power Rangers), the writers behind Kamen Rider actually care about telling a good and proper story. Each entry is about 45-50 episodes, enough time to tell a full and fleshed out story while keeping filler to a minimum.
For example, from the current entry (Kamen Rider Gavv)
My recommendation for beginners is Kamen Rider W as it has an excellent balance of seriousness and humor (it made my friend ugly cry in the end).