"Blade" was before I became a dead set Rider fan, and I remember being intrigued by a sole website in a different language with a couple of pictures of a blue/silver costumed fighter battling obscure-looking monsters in the darkness.
I noticed that around "Hibiki" being aired, a show I ignored because I didn't like the designs.
"Kabuto" was my first internet leaked new series. I remember being really interested because it looked like a post-apocolyptic/future army-esque series. The Rider costume looked awesome to me, as did the monsters, but I didn't pay much attention to the details.
"Kamen Rider Den-O" looked unappealing to me a bit. I didn't like the idea of a Rider being such a pushover, and his companion being (at first I thought) evil, and the monsters didn't look all that great to me. The time travel idea sounded cool though, but I wasn't sure how they were going to pull it off every week (only to watch the show and realize that they pretty much did nothing with the time traveling idea).
"Kiva" had an awesome costume when I first saw the leaked footage, though I didn't like the forms that much (a bit too confusing for me at that time). The Kaijin looked a little generic to me at first (I now disagree with that previous opinion), and I was a bit annoyed by the constant animal-basis all Tokusatsu monster designs seemed to have at that time.
"Decade" was a show I wasn't sure how it would turn out. I didn't like the costume at all, but I thought the idea was kind of interesting. However, I hadn't seen really any of the Heisei shows besides "Kuuga" at the time. It wasn't until after "Decade" that I started watching "Ryuki," "Den-O," "Kiva," and "Kabuto."
"W" I wasn't sure what to think. I was a little excited because the idea sounded cool, but I HATED the "million forms" idea, and I thought Philip looked too flamboyant. Even the first two episodes didn't really rope me in (other than the amazing opening sequence in the first episode). Even with Accel and the Weather Dopant appearing, my standards were low. All three times, the show blew my mind out of my skull (must...resist...pun!).
"OOO" I didn't think looked very good. I didn't like the costume design, and the Kaijin didn't look very good to me. It just looked like a giant toy commercial to me.
"Fourze" is up in the air for me. I like the space theme, but the hair, head design, idea of another 'bad boy,' and even more form ideas worry me. But, we'll see, because this could very well be another "W."
