I quite like Den-O, W, OOO and Kabuto's voices all, but if Kiva is included, then it wins. I kinda think it's cheating, because Kivat II and III were alive, not what I would classify as computers, the way the question is worded, but their voices are the best.

After that, eh, either Den-O or W.

Well, there is Ixa, but his belt has one of the most poorly garbled and phonetically wonky voices ever.

Tie between Blade, Den-O, and W.

It's hard to choose between Faiz and Fourze. There's something perfect and smooth about every part of the Faiz Gear, even mangled English like "Jet Sliger, come closer". But on the other hand, Fourze has some really cool sounds, like Shield, N/S Magnet, and everything from the Barizun Sword and Meteor Driver.
I think I'll give it to Fourze on this one.

Faiz has this cool as ice type of voice that just oozes sexy. I've got to give it to the Smart Brain product placement here.

Still not understanding Fourze. It says States, what Switch is in and On, and Limit Break. All the other noises come from Gentaro screaming his full head off. I love Fourze. I love Meteor more, but I love Fourze. Don't get me wrong. It was a very amazing series. But.. how is the belt getting votes for the best voice?

Because its roboticy voice is really awesome? The countdown alone is enough to put it near my top spot.

Because it... can count. .. So can my brother's dog, but the damn thing still eats it's own poop.

I agree. That voice alone has more charisma than all the Kamen Rider OOO characters combined.

Ah man! I missed the poll!

I would have chosen W. For some strange reason, I love the over exaggerated voice.

HEETOH! JOHKAHHHH!