With the introduction of Halo custom Edition, the HEK and, quite recently, Harbinger, PC modding is, without a doubt, not what it used to be. Apart from a select few, most mods produced are just single models, skins, or 'a bloodgulch mod'. I, personally (although I am sure there are others who will agree) think that there are not enough outstanding mods being produced nowadays.
Which is where you come in. Please post anything that you think helps to contribute to outstanding mod, and, if possible, explain why. Please don't post any ideas that have already been posted, it just creates a lot of repetition, a lot of repetition, a lot of repetition...
Please note that I am asking this for PC only, but if you think that a CE>PC conversion wins the day, post that as well.
Now get posting.

EDIT: Please don't post mods, links to mods, or reasons why they should be in outstanding.