If the main rider actors are unavailable
Masao for Kiva
Kotaro for Den-O
Yaguruma or Kagami for Kabuto

If we're assuming the main riders can't make it, for whatever reason, then how about:
Ghost: Probably Spectre, followed by Necrom, althought I wouldn't say no to Onari or even Akari.
Drive: As much as I love my boy Chase, he wouldn't exist in an altered timeline, so how about Krim Steibelt, not dead? Gou also accepted.
Gaim: Takatora Kureshima is a god, and he needs to return. Failing that, Gaim has a billion rider. Surely one of them has a free schedule, right? Baron loves coming back for random stuff!
OOO: Date and Brotou. Make it happen Toei.
Decade: Literally any of the recurring cast. Yuusuke, Natsumi, even Kaitou.
Kiva: Seconding Otoya. I need to know how many robot puns they can make.
Den-O: Imagin pls. If that counts as Main Rider, then Kotarou please.

I’m curious if the Kiva tribute might involve Masao.

I sure hope so. :rock:

To be honest, I really want Sento and Ryuga are accidentally throwback to 1986 and they meet Otoya Kurenai. I think that's will be really funny. :D

Or, they also can accidentally send to year 2031 and they meet Masao Kurenai.

If we can’t get Kouta back for Gaim then I want Micchy, preferably without his ugly sweater collection.

Makes sense.
Micchy's actor is quite up there these days though so if they can't get him I hope we get banana baron and they pull a Jetman Gokaiger episode.

I hadn't even really thought about who I wanted to see, I was just happy to see some returning faces and riders.

But after reading what you wrote? This! I want this!!

I'd love it if Akiko Narumi would also return for the 'W' episode. I know everyone seems to hate her, but I really liked her character.

Riders in the West? Maybe...

http://tokusatsunetwork.com/2018/10/...rider-fanbase/

http://ukiyaseed.weebly.com/ukiyasee...er-in-the-west

I'm not too surprised by Shirakura's comment seeing how Toei is known to be behind the times outside of Japan.