You could do the Relic quest for a cool weapon and a job specific title.

You could do sidestory quests. Hildebrand can be a lot of fun if you enjoy silly storylines. I haven't tried the Delivery Moogle ones yet, but they apparently give a bunch of background stories.

You could take up crafting and gathering.

The optional raids were already discussed.

Basically, you're at a point where there is so many options available that what to do next is really just a question of what you're interested in.