Choose one goofy made up idea you would add ingame.

[Murder Shepard]

I know that the title says one but I have a few,

charge blade bayonet for extra melee dmg, the ability to customize the primary and secondary colors of all outfits and weapons.

A much much greater chance of getting legendaries from teir 4 boxes bought with bits.

Vehicle attachments like a snowplow blade for the front of my challenger that adds trivial protection but does massive damage

Oh and Joe Teach's jack Drill as a usable weapon' hell yeah!

[Etaew]

Paintball gun, effect sprays a colour for a longer duration, can hit players and friendly NPCs. Mods can change the paintball ammo colour.

[Dar Katan]

Dreams:

• Crafting / Forging System – Imagine going around like in Skyrim picking up ingredients or breaking down weapons to collect different parts to build a special weapon (making grenades, special bullets, shields boosts [adding mod slots to shields], ego boosts, etc.)
• Different environments –*variety is the spice for life (snowy mountains, swamps, forests, etc)
• Outfits that drop off mobs.
• Revamped weapon skill/leveling system –*with each Ego increase you get a certain amount of points to increase a weapon skill. Here is an example: You go from Ego 100 to 150. You get 50 points to up a skill. You go into your Bold Action Sniper skill it gives you 4 options; Bloom, Fire rate, Reload, Critical. The higher each skill gets the more it costs to up a specific weapon skill portion.
• Remove Ego Level on Weapons.
• Fast Travel changes from a loading screen to hopping in a helicopter and flying to the area (think WoW)

[Etaew]

Fast travel involves being deployed Planetside 2 style inside of arkfall, aaaaaaaand splat...

[Dar Katan]

Ooh oh, Falling damage.

[Elastik Spastik]

Flyable aircraft and also enemies that fly

[Toxemicsix156]

hmm if you could shot your guns while you drive that would be legit, that way me and few buddies can commit a drive by GTA style

[Kibblehouse]

How about landmines? 2 types:

First is a Contact or Proximity fused mine which you can drop to get someone chasing you. Think grenades which dont go off unless someone comes close (but definitly dropped, not thrown)

Second could be Command detonated or contact\proximity, but think more like a Claymore or Bouncing Betty. Something made more for prepared ambushes, not easily deployed in combat. Plant your mines just outside an emergency or whatever, start things off and get them to chase you back through your minefield, boom, something like a raider, killed outright, volge? this would be a good opener, finish up with your weapon of choice.

[Etaew]

Borderlands midget style knockback when you fire shotguns

[Blackdeathteal]

Duel wielding pistols like revvy black lagoon style
choppers or at least dirt bikes
new areas or story content