PS4 System Update 4.50 (Gaming)
It adds two great features that I've been waiting for. You can now use an external hard drive for games, like the Xbox One has had since the start. They made it easy to swap the internal drive, and that's great, but it's nowhere near as nice or convenient as just being able to plug in an external drive. I'm glad they finally added this feature.
They've also finally added the ability for users to set custom backgrounds. A small convenience, but a highly appreciated one. Now I have a use for all those Horizon screenshots I've been taking!