This month sees Batman: Arkham Knight delivered direst to your PS Plus account along with Darksiders III. Well, maybe not direct to your account, you still need to log in to the PSN and add them next week, but you get what I mean.
Both are excellent editions to any library. We gave Batman: Arkham Knight an 8 when it released in 2015 and I think I finally got around to playing it last year. It ages well and really felt like the culmination of the Arkham series of games. Darksiders III released last year and I haven't had a chance to give it a go so doing so for free is all the more welcome.