Sony just announced which games will be free for Playstation Plus members during March 2018.
Also, starting March 13 and lasting until April 10, the Dungeon Defenders PS Plus Pack will be available for free. This pack contains 4 Shadow Costumes, 1 Million gold, 5 campaign shard packs, 5 defender packs, and a Ninja Gato Pet.
Finally, and most unfortunately but ineVitable, Sony will no longer have free PS3 and Vita games for PS+ members starting in March 2019. This will not affect any PS3 or Vita games you already downloaded. These games will still be apart of your PS+ account. Sony is just cutting off those two systems, focusing solely on their PS4 system. Exclusive discounts will still be available.