Mercury would mean more Vex, which would be fun. It may also be more of Osiris. More of earth would probably mean more fallen (perhaps the house of kings?). Europa would probably be along the storyline of the nine. Saturn and Jupiter are gas giants and as such, we won't land on them. Their moons had colonies, not them. The Reef really is only known for the awoken in current lore. Personally I'd like to add Mars to the poll. I'd be very interested in what Clovis Bray has done.