Quick correction on the lists:
Decade: Can only turn into the previous Heisei Riders, Complete Form can only bring out the Rider for the hissatsu/super attack (I don't recall the Rider called ever doing more).
OOO: ALL forms have access to the MedaGabryu.

Actually, it's not.
Double's Final Form Ride is to split him into CycloneCyclone and JokerJoker and OOO doesn't have one (To my knowledge).
There is no logical reason for Decade to use it in this battle.

OOO, on the other hand, gains a slew of new powers determined by the combo that aren't available to the individual medals (ShaUTa's water transformation, SaGoZoh's gravity control, TaJaDor's flight, etc), making it much more relevant.

Eh sorry but no one can ever convince me that Decade isn't the most powerful rider. Just based on how his powers work and his (theoretical) ability to turn into anyone (as shown more of in Super Hero taisen).

The only time I recall the other riders appear is because Decade didn''t summon them, DiEnd did. And if Decade summoned them, it was only in their most powerful form via KTouch. The reason I said that the ability is irrelevant is because this is a battle between these 3 and these 3 alone, no outside riders are in the battle, and therefore, Decade can't use his FFR cards

We haven't seen him able to turn into the riders that came after him, the only "New" transformation he had was Ichigo.

But he's not the most powerful. I still firmly believe his fights in [Forgot the name of the movie] were pretty much set up so he could win (Or his opponents held the idiot ball so tightly so that he couldn't lose *Cough*KABUTO*Coughcough*)

Also, Decade can't summon Riders. That's Diend's ability. Decade can only transform into them. So unless there's interference, the only Final Form Ride available to Decade would be the Double CycloneCyclone/JokerJoker.

As it stands right now, I think that Decade has the best chance of beating OOO, taking everything into account, and even then OOO would probably still curb stomp Decade.
I ask: What possible advantage does Decade have that OOO can't immediately counter?
(Double doesn't even factor. He's awesome and all, and if it were a popularity contest, he'd reign supreme, but when it comes to power, he's a couple tiers too low to contend)

Of the three listed he is definitely the most powerful. Between the Kamen Ride and Form Ride cards alone he's a serious powerhouse. Complete Form being able to summon other ultimate forms, though, makes him easily stronger than Double or OOO.

That said, I will always maintain that Kuuga is the strongest Heisei Rider. Probably the strongest Rider ever.

In complete form he can summon the final form versions of the previous 9 heisei riders.

The way you said it you made it sound as if he could freely summon other Riders a la Diend.

Anyway, I guess I'm letting my issue with Decade's lack of character cloud my judgment lol.
Still standing firm with OOO though.

I don't think he ever used it as TaJaDoru (correct me if I'm wrong though)

I'll admit it: I voted for OOO because he has the best costume, and KamenriderOOO is a cool guy. That was about as deep as I got xD

I only just started Decade. I've seen all of OOO. My decision is probably biased a bit because of that.

Edit: W is pretty awesome, but he's probably more knowledge than power. This is one situation where knowledge does not equal power.

Voting for OOO too. Like matrixbeast said, OOO could easily counter any of decades past rider abilities. Decades complete form can only use finishers/ one attack from the other riders final form, plus he has to keep pressing a button... OOO could easily blind him as RaTorATah, causing him to miss, or freeze him with PuToTyra and finish him off. W... Wouldn't stand a chance =p

Since we have 10 total riders competing in the tourney, whoever gets second place in this battle will be featured in battle 4.

Kamen Rider Similarities Tourney 1, Battle 2- Sometimes Red
 

This time the battle pits the Riders whose main featured forms are red in color.

Kamen Rider Kabuto (2006)

VS

Kamen Rider Den-O (2007)

VS

Kamen Rider Accel (2010, Kamen Rider W)

Lets review their powers and strong points!
Kabuto:

• When first transforming, Zecter can defend Kabuto, Masked form armor can be ejected and cause damage
• Can Clock Up- allowing him to move faster than the eye can see
• Most Powerful Form: Hyper Kabuto
• In Hyper Kabuto form, can hyper clock up, allowing him to move faster than before
• In Hyper Form, can use the Perfect Zecter, allowing him to summon other Zecters to him and utilize their powers for the Maximum Hyper
• Kabuto Extender is his Rider Machine, able to switch from the fast Masked Mode to the offensive-oriented Ex Mode
• Weakness- Requires the Zecter to henshin. If incapacitated, can't transform. Tends to be overconfident at times.

Den-O:

• Has 9 different forms, each with their own skills
• Wields the Den-Gasher, a weapon with multiple weapon configurations
• Can travel through time with the Den-Liner, which has multiple powers in each train car.
• Liner Form is the most powerful form the Rider can take when Imagin are incapacitated, able to use the Den-Kamen sword to communicate with them
• Most Powerful Form: Climax (TV), Super Climax (Movies)
• Climax is a balance of all the Imagin's powers combined, giving him mulitple finishers
• Super Climax allows him to fly, and grants him more power
• Weakness: Can't use other forms if Imagin are incapacitated, can't henshin if Rider Pass is taken from him. Imagin may fight against themselves, causing Den-O to switch forms or lose access to his other forms if their fighting continues.

Accel:

• Has 3 forms (4 counting bike form)
• Wields the Engine Blade, which has 3 different attacks (Jet, Electric, Steam)
• Bike Form allows him to travel without the use of a Rider Machine, can combine with the Gunner A, to use a powerful shot, or a Maximum Drive using the Engine memory
• Most Powerful Form: Trial (TV), Booster (Movies)
• Trial allows him to move at fast speeds, giving him the ability to slash or hit an opponent multiple times in a small amount of time
• Booster allows Accel to fly at fast speeds
• Weakness: Needs Gaia Memories to Henshin, Trial takes away Bike Form and offensive power

Whoever comes in second in this battle will be featured in Battle 4

Who is the more Powerful Rider?

I'm torn. Den-O is my first Rider series(that I'm still yet to complete ._.), but Kabuto's probably the strongest from what I've heard. Hmm...

Kabuto, no contest =p He looks awesome, is faster than both of them (Trial's speed is time limited right?) and can time travel without the use of a train =p

Kabuto can travel through time with the Hyper Zector.
Need I go on? :lol

Anyway, I think you really need to work on your "Weaknesses."
They all boil down to "Can't henshin if they don't have their henshin device."
Mention Kabuto's cockiness, the Imagin's argumentative nature, etc.

I voted, obviously, for Decade.

Of these 3, definitely Kabuto.

I believe he did in the finale.

Fourze.

This battle is technically closed as W was pronounced the winner and is currently in the tournament stage

OOO for the win! I have only seen some of all the series but it sounds as if OOO could just go PuToTyra and knock them dead

Huh, this is a tough one. I was initially inclined to go with Kabuto because lol Clock Up, but then I realized that Accel Trial is probably fast enough to keep up. From there I guess it comes down to who's the better fighter and in that category I think Tendou does edge out Terui.

I haven't seen Kabuto, I really Den-O, and Accel is pretty cool. I have no idea who to pick. I suppose I will mull it over more and choose later.

EDIT: I doubt there will be enough votes to shift the lead by the time it ends. I'll go with Kabuto. A decision that is completely void of bias.

Haha. My bad.

I voted Den-O. Because he's been on my side with Goseiger xD

This Battle will close on Thursday so the 4th battle for this Tourney can commence

This Battle will close on Thursday so the 4th battle for this Tourney can commence

I still don't see what Decade has over OOO.
Tsukasa is said to be a genius, but his fights don't show that. His fights are just him brute forcing through his enemies or fighting fire with fire.
He can become any Rider? Fine. He doesn't have Kabuto's skill, Ryuki's attitude, Den-O's spirit or support, etc.

Well, that actually depends on what Clock Up actually does. Wouldn't super speed be irrelevant if your opponent slowed down time?

Ironic that Fourze lost by 4.
But I'm still surprised that it wasn't like Double: 20 Fourze: 2 or something like that :lol

Holy crap, I just realized that :lolol. Well, Fourze, like all the other "Losing" riders, will have a second chance in the next tournament

And Kabuto is way in the lead!

Decade is ahead of OOO by two!

Onore Onore ONORE!
Everything Decade can do OOO can do better!

Well Matrixbeast, even if OOO come in second in this thread, he will be part of Battle 4, so he can possibly win there. Honestly, as a huge OOO fan, I can say that him and Decade could have an even match, but most people seem to be going on Decade's powers over the riders before him.

But Decade can do everything better than OOO! :O Quite the conundrum...

Hush you :p
But seriously, what can Decade do to place him at an advantage against OOO?

lol I'm just playing.
I'm completely against Decade, and I already know I'm completely biased against him thanks to my massive dislike towards him :lol
Every time I see him use another Rider's ability, it's pretty much a "How dare you stand where he stood" moment for me :P