Robotech

Operation Mirror Image
Features background, mecha, and ships for a Rifts-crossover campaign set after the television series.
http://ksantos.tripod.com/robotechrpg/

REF/Mechanoid War
A play-by-email campaign set on the SDF-3 after its disappearance.
http://www.geocities.com/refmecha/index.html

Robotech RPG - Mike Perry
Based on the Palladium Books RPG system. Great resource for e-mail campaigns.
http://www.kent.net/robotech/

Roleplaying Macross
Notes on adapting Macross II rules for use with games based on the anime series Macross Plus and Macross 7.
http://unsd.macrossroleplay.org/rpg.php