Given Microsoft's "blockbuster" April on Games with Gold (The Wolf Among Us, Sunset Overdrive and Xbox 360 titles Dead Space and Saints Row IV), it was always going to be tough for Sony to counter, but their offering for April with PS Plus ain't too shabby.
On PS4 we're getting Armature Studio's team-based space-shooter-meets-RPG Dead Star (that is launching as a PS Plus title) and Ubisoft's Zombi (originally ZombiU on Wii U). The PS3 and PS Vita offerings are perhaps a bit on the less spectacular side with I Am Alive and Savage Moon on PS3 and A Virus Named Tom and Shutshimi on PS Vita, but the upside is that you probably don't own many of them already.