Whats the best Combat based activity to make gil?

People always fail to mention the easiest, quickest way to make money in this game.

Sell NPC shop items in the AH. People are too lazy to look up or travel to w.e you get the items from. Find some items being sold for high amounts (like Emperor's gear) and make dat cash. 15 minutes of your time in research and 2 whole minutes to get it done. Then you can do your dailies or w.e

Or if you want to be crafty, buy things in other servers and sell them back in your server where the price is double or triple. Especially new released stuff. Granted I haven't done that in a long time so I'm not sure if they did anything to now prevent that.

Combat based? Do the daily roulettes with some mates each time, get a pack of gil. Desynth the junk armor/accessories and sell the mats to Market Board. Use the Allegory if you wish for free mat selling, or use them to craft Pots for raid.