Do you guys are not tired with animal mechas ?

I found out who ZyuohCondor is. It's ZyuohEagle and ZyuohBird fused together.

We already have so many cars, trains, and spaceships in the past too.

It's either animals or vehicles, but it depend on what type of animal species and vehicles. Also, the gimmick of the year is important. They need to stop giving red the T-Rex, giant birds (falcon/condor/eagle), and big cats (Tiger/Cheetah/Lion). I said it so many times.

Do a full on insect and arachnid team with insect robots like B-Fighter Kabuto. We already have beetles mechas from Go-busters and Hurricanger and bugs are very popular in Japan. The concept of Pokemon was based on bug catching too. Speaking of that, the anniversary movie is coming out too.

As long we have KR, is never gonna happen.

I disagree. You never know. Besides KR had non-insect riders since Amazon. KR does have the insect motif down but I would not be surprised if they are saving it for a time when they really need to use it for Super Sentai.

I don't think that's an issue, there hasn't been a full-on insect Rider since... the Gatakiriba Combo from OOO? And that was just an alternate form as well.

Kamen Rider really isn't about insect-designs anymore, we can consider ourselves lucky if the suits even have compound eyes or antennas these days. If Sentai wanted to do an insect theme they could do it, they just had to make sure not to make the suits too Rider-esque. Just avoid compound eyes in favour of visors and you're good to go.

And they could really go ham on the mechs, in that regard Kamen Rider isn't even an issue design-wise, just make sure it's not too Metal Heroes looking.

The mechas could be vehicles motif like B-fighter/kabuto and the Gouraijers ?

you cam argue that ghost got a firefly motif. out of all the heisei series there's only kuuga, agito, faiz(arguable), blade, kabuto, and decade based on insect and arachnid. after that we got w and Os only if we exclude movies riders like KR3.
If Sentai do a insect and arachnid theme series then the rhinoceros beetle and stag beetle gotta be the red because they're probably the T-Rex of bugs in terms of popularity. They were used by the "6thish" Hurricangers and Go-busters even thought the 2 aren't insect theme.

How would be you guys the perfect anniversary season ?

Something grand, but it doesn't need to be like Gokaiger/Decade, but not subtle like Boukenger/Kabuto either. Don't be a space theme Sentai again. I kept thinking Kyuranger is the anniversary season instead of Zyuohger.

Anyway, if we're going to take my insect motif idea in to account then I would like a high tech military base to pay tribute to classic Sentai even though the last 2 aka ohranger and gobuster bomb. However, sentai is airing at a later time, so maybe Toei could give a darker tone series a chance. there could still be comedy in it and doesn't need to be like Amazons. The villains would be some accidental lab creations went wrong along with some defected researchers that created them, so the government set up a base with natural gifted and biological enhanced individuals to take them down. It would be nice that 4-5 of the past red could appear in each major arc to actually help push the story further instead of just random fanservice. Maybe the Taisen movies can truly incorporate Sentai in them and make it a small vs team up with that year rider series.