dude that costume is awesome, i mean for an evil kuuga it looks perfect

No. Extreme is the worst looking Final Form IMO as well. As far as the main Riders go. Nothing can top DiEnds final form though.

Image is broken.

And I don't think so. Ultimate's black with gold accents really worked. Just black with shoulder pads of doom.
Rising Ultimate felt like they chopped up Blade King Form and super glued it to Kuuga.

That's not an Evil Form

wat do u mean he was totally evil wen he got that form

Only the black eyed version is evil and that was temporary. The red eyed version is the pure form he accesses when decade uses the K-Touch to turn all of the Heisei Riders into their final forms.

And worst final form? Not CJX. I'd have to go with Accel Booster or Kabuto Hyper.

gatack hyper's worst

I loved Hyper Kabuto. It's so cool ^^
If we're including non-main characters, then Diend Complete takes this by a mile.

Rising Ultimate is a mess. The real Ultimate Kuuga is a beautiful suit with the black and all the gold lines. Rising Ultimate looks like someone let Xzibit take Kuuga to a body shop and go nuts on him. The whole concept of the suit doesn't even make sense if you know how Kuuga's Rising and Ultimate forms worked. I don't even count it as a final form - it's just some terrible thing that should have never been (yes, I'm totally getting the Kiwami Tamashii).

For my money, the worst final forms are Decade Complete and Climax Den-O. Again, both of them are kind of a mess. The huge card row on Decade's chest is incredibly silly while the masks all over Den-O look ridiculous.

I actually love Decades final form but i realize I'm in a minority on that one. If there's any Den-O Form to hate it's Liner. Now that one was an odd mess. I like it well enough but I still don't understand why it takes on the color scheme and design of Kingliner and that headcrest/spoiler is way over the top. Again it isn't my least favortie design. Honestly the proportions and goofiness of Kabuto Hyper have always bugged me. And Accel Boosters chest bothers me as well. It's why I don't particularly care for those 2.