In my opinion Halo Reach has the best armor in Halo. I would like too see something similar in Halo 6 where you can change every part of your armor not like in Halo 4 and 5 where you can pick a body, helmet, and visor. Like Halo reach where you can pick a different chest, left shoulder, wrist etc. Also there should be a credit system that you earn credits through playing the game to buy armor to your character. Nothing to give you an advantage over your opponent. I think that armor and customization is overlooked but I think it is a big part of the game people care about.
Feel free to add to one of the existing wishlist threads in GD.