I voted for Ichigo. OOO is powerful and all, but he doesn't have the skill and power one gets from forty years of destroying evil. Honestly, even with all the form changes I just don't think Eiji is all that good of a fighter. Hongo is.

I still have to go with Kuuga as being the overall most powerful. He's a skilled fighter, he never backs down from a challenge, constantly seeks to improve his power, is able to overcome the darkness at the center of Kuuga's power, and has a really versatile mix of forms available. Plus there's the whole part where Rising Mighty can blow up an entire city block with a Rider Kick and he still has two forms that are even stronger. Honestly, if he ever had to I'm pretty sure Godai Yusuke could mop the floor with any other Rider.

Hey, come to think of it, where the hell is Kuuga in this Rider poll thing?

Kuuga was put up against Ichigo in the first ever similarities battle, but people voted for Ichigo, which is why he was able to enter the tournament. Kuuga will take part in the second tournament though

Just look at Decade's skills and traits.
-Can use the powers of all preceding characters.
-Is cold and aloof despite the loving friends.
-Has girlfriend who inexplicably loves him and would do anything for him.
-Has amnesia.
-Is a genius and perfect.
-Has one flaw that's not really a flaw.
-Can outfight the best fighters.
-Can use every power perfectly from the get go.
-Has a superpowered evil side.
-Everyone inexplicably likes him from the moment they lay eyes on his stupid haircut.
-Can freely act like a jerk and never get called out on it.
-Is the destroyer of worlds.
-Is too good for this sin filled world.

Many of these can be applied to Kabuto. Thing is, it's either played for laughs or Kagami is too busy making the story amazing to care. Decade was too busy relegating Kuuga to "Bystander who can't do anything so Decade will always be the hero and look the coolest" to make that difference.
Tsukasa can't carry a series. Yuusuke never got to do anything. Natsumi is a horrible female character. And the grandfather (Forgot his name) was the only tolerable character.

ONORE! ONORE! ONORE!

That wasn't the case in OOO, Den-O, All Riders: Let's Go Kamen Riders! Granted, he had Nigo's help, but he also reduced multiple kaijus into puddles.

So what it comes down to is Skill vs. Power.

As for Kuuga, he may be superior to OOO. I wasn't really thinking about him when I made that statement :lol

We have the guy who creates multiple time paradoxes and survives... against the guy who IS THE PARADOX, and fully capable of creating more. I've said it once, I'll say it again: D-D-D-DECADE!

He's not a paradox.
He had one mission. To destroy the AU Riders to prevent the worlds from merging. He instead befriended them and essentially doomed them all by allowing the worlds to merge and start the Rider War.
Then lots of laser beams and the writers forget that stories should have endings.

Decade isn't a paradox. He's just an idiot.

Kabuto survived the Shibuya meteor and the Zect vs. Neo-Zect business, pulled the Hyper Zector through time, defeated the man with a blue rose, threw another meteor into the first meteor to reduce the size, changing history and setting off the events of Kabuto, and gave his younger self his Rider belt.

Decade must destroy the AU Rider worlds in order to save them. That's a paradox.

Kabuto changed history, but in order for those changes to remain permanent, he'd have to take the meteor back in time to Shibuya once that meteor arrives in the show's timeline. Otherwise, he'd cause a Grandfather Paradox.

Decades mission is technically a paradox then, not the man himself as he proved he could do what he wanted, and by doing this he never actually went through with the paradoxical scenario.

Also being a walking contradiction doesn't make you super powerful.

As for the second bit... what?

EDIT: I had a quick read on wiki about grandfather paradox and I don't see how it applies... or even if it does you can argue it as a parallel universe scenario. =]

No, it's not.
Note that the Rider who gave him the mission was the original Wataru, Kamen Rider Kiva. In the AU, he found a child version of Wataru, the AU Kiva.
Decade's mission was to destroy the AU Riders so that the Original Rider worlds would survive (That's why the original Riders came to kill Decade during the end).

And Kabuto's scenario isn't like that. The meteor that crashed into Shibuya was the remnants of the two meteors that collided in God Speed Love (The original, gigantic one that turned Earth into a deserty wasteland, and the smaller one that Kabuto pushed into the larger one when he traveled back in time). It's not a grandfather paradox because, as Kagami's disappearance on the pod back to Earth revealed, the timeline presented in God Speed Love ceases to exist because the circumstances that led to it were radically changed.
In short: There was no paradox because that timeline and universe (Neo-Zect, Caucasus, Ketaros, Hercus, etc) no longer exist for the paradox to occur.