Multiplayer Loadouts

Free For All / Team War loadout:

Pretty much every player uses the following standard, most effective loadout.

Armor Dreadnaut can fit max weapons, faster than Assault. Assault doesn't really have much more armor to make it worth using.
Rifle attachment Gauss rifle Does a lot of damage! I think maybe 1/5 total armor
Heavy weapons 2x Guided Missiles Hard to dodge, do a lot of damage. If you really want to annoy people, bring ECM grenades!
Mines 2x remote mines, 2x prox mines When you equip one remote mine, there is a delay before your can detonate it. If you equip two, you can deploy the mine with one mine button and immediately detonate it with the second mine button. You can actually whip remote mines around.

Alternately, twin prox mines is good for preventing access to choke points that gets used fairly often too.

Folks use timed less but they do so much damage but require a bit of luck really.

Capture the Flag loadouts:

The two roles in CTF ammount to the typical Fighter loadout and Flag runner

Fighter

Armor Dreadnaut For the same reasons Dreadnaut is king in other game modes, the same loadout works in CTF.
Rifle attachment Gauss rifle as mentioned above, its by far the best attachment
Heavy weapons 2x Guided Missiles Hard to dodge, do a lot of damage. If you really want to annoy people, bring ECM grenades!
Mines any Double remote mines is still handy. It is tempting to use prox mines to mine the base but DONT do it because there is a bug where the flag gets permanently stuck to the flag runner if they die by prox mines while carrying the flag!

Flag Runner

Armor Scout can fit max weapons, faster than Assault. Assault doesn't really have much more armor to make it worth using.
Rifle attachment Gauss rifle as mentioned above, its by far the best attachment
Mine remote mine, maybe timed? On scout armor you only get one mine so remotes are less potent but still potent enough. I think a carefully placed timed mine might do well to cover your escape if you drop it before you grab a flag and double back right over it.