[Kamen Rider Lucha]

I have a problem with SO MANY final forms.

Both Ryuki and Knight Survive are dreadful.
Decade and Diend Complete make my eyes hurt.
Kiva Emperor Form is garish and awful and such a disappointment compared to the base form (and the other monster forms).
Fourze Cosmic states is garbage.
I "get" Gaim Kiwami Arms, but I don't really like it -- especially compared to the far superior Kachidoki Arms.

But the kicker for me, if we're including secondary riders, is Meteor Storm. Base Meteor is hands down my #1 favorite Kamen Rider suit design, and it's close to the top of my all-time favorite super hero designs, period. I felt gutted when I first saw his final form, and I felt like I'd been stabbed in the face every time Ryusei transformed into Meteor Storm instead of Meteor.