Examples: (Will Edit)
Gundam: Obviously while Gunguy is the immediate response to what people believe they're are countless variations of Gundam inspired designs. You have have a large variance of shaped V-fins and great deal of them are often in another color and sometimes even that is not enough.
Macross: Having the signature plane design can be a plus for potential plane//jet body mods.
Gurren Lagann: More or less having Shades on your chest being the obvious... Drills are not just enough anymore we would like to have more chest armaments. Hell a fremere recolor would be popular.
King of Braves GaoGaiGar: Now we're incorporating vehicles and animal themes into building a design is rather a strikingly fun project item devs can fall behind, this also follows Power Ranger's Megazord and Voltron logic as well.
Zone of the Enders: Even non traditional mecha designs can create some pretty well inspired designs and in some cases Gaia can even do well on it's own with it's own materials.
Voltron: Asymmetrical design. Honestly you guys need to go back to the days of Automaton wears which had individual limb poses and can still layer to a degree. Think of the potential layering this with multi colored limbs it can spark something bigger than just Voltron.