I would pay good money for a Macross RPG.
The mecha RPG space is dominated by Gundam -- not in terms of actual licenses, but in terms of the types of stories told. Lots of focus on detailed mecha construction and mecha combat, etcetera. Very 'militaristic', and even though Macross always features a military squadron, it is not a military series. To me, Macross plays out on three levels:
- The story level ("During the initial attack, we accidentally jumped to a Jupiter orbit, now we need to get back to Earth");
- The fleet manoever level (like how supply ships and support cruisers support the Macross-class main ship, or how enemies bring their main guns in position);
- The mecha combat level (which is traditionally the level that all mecha RPGs focus on exclusively).
And there's a fourth dimension: there are always civilians, and their stories always mix in with those of the mecha pilots.
The system should allow for cinematic combat (no detailed hit locations or 25 different things to track!) and great social interactions, focusing on archetypes and their role in the story -- something with Apocalypse World-style playbooks would probably work quite well.
Of course, the swamp that is the licensing of the Macross TV series will ensure that the RPG would never be released in the US, which basically kills any prospect of making it even remotely a commercial success...