I've always been a "If it ain't broke, don't fix it." kinda guy, and that is exactly the stance I took with this 2018/2019 upgrade of my ITX build which will hopefully last me a few years to come. It was important to me to re-use some of the components I already had instead of going all out and spending unnecessary money, so I kept the case, PSU and CPU cooler the same as my previous build which helped me save some extra £.
After being sadly disappointed with the i9-9900K price to performance ratio, I decided to jump back a generation and pick myself up an i7-8700K and pick up a new accompanying Z-390 chipset motherboard. Going for a newer chipset should keep me going for a couple of years to come when, hopefully, the prices come down on Intel's new i9 mainstream processors. Compared to my ageing i7-6700K, the i7-8700K would still give me great performance, and another core to boot which will help me with gaming and streaming at the same time. It also helped that I managed to find a brand new i7-8700K at literally half price at my local CEX which spurred me on to upgrade in the first place!
A few notable upgrades since my last ITX upgrade (which you can find here https://uk.pcpartpicker.com/b/8wLD4D) include:
nVidia GTX 1080 Graphics Card Samsung 970 EVO 250GB Boot Drive Intel Optaine 32GB module to accelerate my 3TB Seagate Barracuda "Game" HDD
Overall I'm really happy with this build. It's silent, compact, and still performs like a champ, plus I didn't have to break the bank doing so either.