Somethin I have been discussing with a few friends is the ability to customize weapons and ships. This could be as simple as adding an empty slot to exotics and Xur sells a "random" perk every week for 10, 15, or 20 strange coins depending on how beneficial the perk is. It could go as far as having the gunsmith create a brand new gun, requiring you to dismantle X number of weapons of the type you are creating with whatever perks you want. If you want void/arc/solar attached you dismantle X number of weapons to get that. You could also randomly earn a perk from nightfall or chests. It would need to be semi difficult to achieve so everybody isn't running around with a multi-light attached autorifle with 100% stability and 100 rounds a clip. Ships (although decorative) could be the same. You dismantle ships to get the parts you want and can attach/arrange them as you want to create your own unique ship. You could gather ship parts from chests also.