Clearly the worst antagonist is Gif.

I haven't seen Den-O yet. So hey, maybe I will find him more boring or poorly written. Only time will tell. For now tough that award goes to Masamune.

He doesn't though. He literally just walks into the building and pulls the Cronus Gashat and Buggle Driver out of an unlocked drawer and proceeds from there.

That they never actually show him doing it is proof enough, but there's also how he only ever focuses on business as well as how he sat in prison doing nothing for 10 years. Even when he did use to run the company, every single flashback shows Kuroto doing all of the programming work, never Masamune.

The most interesting thing is that while Gif was a silent piece of stone, he quite suited most viewers as the main villain. In fact, he was disappointed only after he voiced his motives.

I've honestly never considering who I think the worst villain is. Giff is certainly fresh in my mind, but when someone mentioned Kai from Den-O I went "Den-O had an antagonist?!" before slowly remembering that he existed. Making that little of an impact on me definitely gets my vote for the worst.

I'm not sure who I'd consider my least favourite. Usually the villains are either good for me in some way or don't do anything to directly bother me. I guess Horobi or Giff.

I'd probably vote Masamune as my least favorite. He's just generic corpo man who's a master planner but with none of the charm that Evolt had.

For funsies, I watched Kamen Rider Ryuki's Hyper Battle Video which is a very fun and harmless little video and it honestly makes me wish it is one of the special features for Ryuki's upcoming Blu-Ray release.

Sitting in prison is also part of his plan :p (Patient Zero). But yeah, focusing on business part is also seen in his game designs like giving Gamedeus generic boss one-liners. Kuroto is certainly more talented and passionate in programming just that doesn't mean Masamune can't.

Shows that Revice doesn't quite to know what to do in later half juggling all the buildups, I too think Giff is more better suited as unseen antagonist that fuels the agendas of each side, or if they want to make him an active antagonist, use him in Akaishi's place.

KR seems to have loads of boring and uninteresting main antagonists (though they had lots of secondary or below antagonists that are interesting and memorable). The main ones are the likes of Tennoji, Mishima, Kai, King (Kiva), etc.

I feel that one shouldn't complain about villain lacking charms as they're meant to be hateable. Humans' dark impulses do often make villains feel entertaining though.

Gonna have to be careful in this thread, because I just watched episode 2 of Geats. This seems like it's going to be a fun ride. I also really like how (so far) the main character isn't the title Rider - is this the first series to do that?

There is also Hibiki and Kabuto. Yes, and in Agito, attention to the three main riders was plus / minus equally.