One of my favorite plugins is VFB+ that adds a lot of functionality to the Virtual Frame Buffer (http://www.monotoneminimal.com/vfb). I learned this week that this previously commercial tool is now freeware. Go get it!
Also, in case you live under a Rock and didn't hear, Substance Designer 6 (https://www.allegorithmic.com/products/substance-designer) came out this week. I've only briefly played with it, but obviously anything that Allegorithmic makes should be in your toolkit. I noticed that Steam gave me a discount for it, but I don't know if that's because I previously bought SD4/5 or it's a general thing.
Also, Vray 3.5 came out in the last couple weeks. I now own Vray and will probably start adding some Vray support into the material exporters and Sky Writer. There is currently a great deal going on where you can get VRay + Phoenix FD as a bundle for a reduced rate (https://www.chaosgroup.com/phoenix-fd/bundle-promotion-2016).