I 'always' run into this problem.

Work on master gearing my gatherer? My crafter? SB more materia for the meldings? Finish the gathering achievements? The crafting? Run around grabbing unspoiled nodes? Try and further deck out my FC room?
Or switch focus to combat? Run dungeons for tomes? ST for weekly drop? Finally bother with EX's? Continue Animus book? Hit the daily marks? See if elite marks aren't terrible at the moment?
Run FATE's/dungeons to level lower classes? Try and better gear my other 50's?
Maybe work on desynth? Gather mats to raise the main, or work on second/third desynths? Spam for demi's, or push to raise skill with 1stars?

And I haven't even bothered to 'start' the sightseeing log yet, was waiting for the groups of people to stop standing around the target locations. Kinda kills the mystery XD.
Thankfully the challenge log just kind of happens alongside everything else, but still...

Not enough time in the day -_-