ZX would have had a fantastic series, but I still don't like his costume all that much. I agree he does deserve it
ZO, I think deserves a full show, that was an awesome movie one way or the other and they could have really expanded on it with a show. shins full potential was already fully established in the movie and I really couldn't see where they'd be able to go with it afterwards, but heck, they could suprise me. J, I agree would probably be just an okay show. I'm not all that cool about a giant kamen rider.
also, I know I might get chewed out with this one but, I think a short 26 episode shadowmoon series would have been great!! where he starts to turn from his evil ways and slowly turns into a rider himself. if they hadn't done those episodes in RX, I would have said they had no need but after them I think it would have been great to explore.