Kamen Rider X - His design came off as rather lazy to me, especially compared to his fellow Riders of that era.
His suit looked too "homemade", as if Jun's father had taken some old clothes from his closet and put some red plastic-tape over it.
His jacket often got really wrinkled under his belt as well, which made the suit look even worse.
Kamen Rider ZX - Rider Thong.............................. This was around the same time we got the Space Sheriffs and Dynaman. You can't blame the time for that suit design.
Kamen Rider Black RX - As an upgrade to the Black suit, I found it really disappointing.
The Black suit had cables and wires to cover the areas where there was no armor, but the RX suit had green spandex instead. How lazy is that?
And I absolutely hated the helmet and neck design. It made him look like a hunchback.
Kuuga Growing Form - I liked the idea of a base-form for Kuuga, but god it looked crappy.
It looked like his chest armor was too big for him, and you could really tell that it was plastic.
The small horns didn't exactly help either.