Classic Mazinger Z (or the new one who seems fairly close) Angoku Daishogun Great Mazinger Getter Dragon Big O Big Duo Big Fau Plenty of Guyvers Dancougar Gaogaigar Archer from Fate Stay Night Casshern Ken from Gatchman Golion (Lion Voltron) Voltes V Raideen Jeeg Zambot 3 And any other classic mecha of the 70s or 80s that I have missed, who has been a mainstay of Super Robot Wars. I'd love to see all these classic mecha given life as Revoltechs.
Fraulein Lucy/Nyu and Nana from Elfen Lied King Kittan (or any other GL mecha really) and fraulein Nia Lion Voltron would be pretty cool too.
I'd love some FLCL Revos. Canti in the regular line and a Haruko for the Freulein line :3 (that would even open up some milking possibilities, Haruko in her various outfits and Canti as either red or blue)