Better than me:

Decade: first 3 episodes + All Rider vs Dai Shocker
Double: first 3 episodes
Den-O: finished
Kiva: can't watch due to technical limitations :(
Fourze: Finished
Wizard: ongoing

Watched episodes 1-4 of Black last night. It's really good for treadmill viewing since there is aprox 4 mins worth of actual dialog in each episode and 16 of action. The rest is credits and theme song. I like the mystery and darker tone of the show.

Black is probably my favorite Rider show of all time. You definitely can't go wrong with it. Just don't be surprised when it starts getting a bit more episodic.

Yeah, the episodic thing already kinda started with 4. I'm ok with it. I'm curious to see how the show goes knowing he had to fight all these mutants with no 2nd rider or power up's.... Guy doesn't even have a sword! A chop , a kick , a punch and a bike. That's it!

Black may not be my favorite show but it's easily the best out of all the Showa Series (and most Heiseis) that I've seen.

Well, he does get a second bike.

Just watched the Faiz movie, paradise lost.

To anyone curious about Faiz, just watch this =p You get too see all the cool designs, minus Deltas and it just works better anyway. Orga and Psyga are awesome designs and the fights where pretty cool too. Especially Psyga vs Faiz.

Bad points... Err slightly pointless start, that just felt like it was there to prolong the film a bit/ shoehorn in a prophecy. Kiba is as wishy-washy as he is in the series too.. "I'm Kiba and my opinions change frequently, usually because I've been beaten by somebody who opposes my ideals so I side with them."

I really hope the Psyga and Orga S.H.F's get released... Now onto Blade.

I started watching my first KR series, Kamen Rider W, a while back. I'm already on 39 and you know what? I fucking love this. It's just so much fun to watch. I'm not big into anime or Japanese shows in general, but I'm hardpressed to say a lot bad about this show. I love the Rider designs, Skull especially. Most of the main characters are great and fun to watch, and I'm hooked on the story. It's making my want the toys. I have MG Figurerise Skull and plan on getting Accel and Double, but I also want the SICs. (Or the Figuarts if they weren't so hard to find and expensive)

I'm glad I decided to expand my horizon and check out a show I normally wouldn't bat an eye at. What would be a good, more current Kamen Rider series to watch next? Kuuga? Fourze? I've heard good things about both of those.

Most people will point you to OOO, Fourze or Wizard if you're enjoying W. Everything before W had a much different tone, barring Den-O. If you want something that's a bit more traditional, Kabuto isn't a bad place to go, but it certainly doesn't have the same kind of flashy, comic draw that more recent shows have.
I'd personally recommend Fourze, but that's because I'm horribly biased towards space-exploring high school adventures.

Up to episode 5 for W, about to start it up.

Really enjoying it so far.

And I will second Brainchild's recommendation of Fourze, I really genuinely enjoyed my time watching it, kinda sad it's over. Also suggest getting caught up with Wizard, also a great series so far.