Some of my picks would be - Tucker and Jr adventures between the end of season 5 and when we see Tucker again in season 7 - Pretty much anything Chorus related post season 13 - The various events Sister hosted at Blood Gulch. I know they've been described, but it would be fun to actually see them. Plus, more Sister is never a bad thing - More stuff with the mercs! Supposedly Miles had ideas for a full on spin off?! - Prequel content for RvB Zero. There is so much potential with things introduced in RvB Zero, if only time was spent exploring them