Finally decided to upgrade after my first build in 2012.
Some rationale for the parts I bought:
The CPU cooler is still the same one from my first build. It served me well for six years, so I saw no reason to upgrade to anything different other than the fans. I decided to get Noctua's NF-F12 industrial lineup due to how insane they performed in terms of static pressure and airflow. I followed the same reasoning for my case fans and bought the industrial NF-A14s.
I originally wanted 32GB of RAM for this PC, but as you've seen,heard, and read from hundreds of other people, RAM prices are horrible now.
Pretty much the same reasoning behind RAM. I was also not about to pay MSRP for graphics cards that are two years old at this point. Will get a 1180 or whatever the equivalent is when NVIDIA finally releases that.
I bought the Dell U2515H a couple of years ago without the intend of really gaming on it. It still is a superb monitor, however, as the colors on it really stand out. 1440P also helps. I will probably get something like a Dell S2417DG in the future and make the leap to higher refresh rates and G-Sync.
Bought my first M.2 SSD this build. Love it. Not needing to connect it with any cables is great. The two HDDs I have are for my games/storage. The 1TB is faster, so that is for my games, while the 4TB is for music and videos. I do have plans of buying a 2.5 SSD for my games, but a GPU and monitor have priority.
Let me know if you have other questions about why I went with something or just questions about the build in general. I was really pleased with how it came out looking in the end (after a grueling 6+ hours of making sure the cables were as organized as possible).