[Soundwave]

Personally this is my choice for the more debatable riders.

Kuuga - Ultimate
Because this is the actual Kuuga's final form. Heisei Riders from Decade series always seems to be replica's of the actual riders to me.

Den-O - Super Climax
Because it's more powerful then Liner form. Has all 5 imagins fused with him, as per how his base forms are but this is with all 5. Liner form to me, is like a form without the imagins.

OOO - Super Tatoba
Because it's the power up of his original medals. If Putotyra is the final form, what makes the core medals? Just because it's stronger becase of the berserk nature, does it mean it's on a higher league then the other medals?

Fourze - Cosmic
Almost the same reasons as Den-O. A combination of all his switches. Did not choose Meteor Fusion because he needs the Meteor switch, which I suppose rightfully is not his.

Just my 2 cents. :P