Final Fantasy XIV (PC, PS3, PS4) can be played for free for 96 hours until January 4th.
Since December 1st, there has been a “Free Login” campaign for Final Fantasy 14. Until January 4th, returning players who have not had an active subscription in the last 30 days can spend 96 hours in Final Fantasy. However, you must own the retail version of Final Fantasy XIV, which means you must have been a player at some point.
The offer is valid for players on PS3, PS4, and PC.

FF14 frequently offers such campaigns to entice returning players to check out what has been newly added since their departure, aiming for them to resume their subscriptions. The MMORPG from Square Enix is one of the few games today that still relies on a subscription model and does not intend to change that.
By the way: The 96 hours count down from the first time you log in. Therefore, you should do this when you have enough time to play in one go.
Final Fantasy XIV: Free2Play? No, thanks … maybe if WoW starts doing it