This is my first self-built box. The purpose of this machine is photo editing and storage, lots of web browsing, occasional coding, and typical office work. I chose the components to allow for gaming in the future, but currently only console game. They were also chosen to give the build a little flare -- if I am going to build a box from scratch, I want it to look good.
I went with the U2 for its extremely small footprint, metal construction, and sleek appearance. I am happy with that case now that the build is complete, but there are no cable management provisions and space is tight, so assembly and cabling was tricky.
I chose the 4690K and Z97 combo not because I plan on overclocking, but so I can in the future if I need more performance from this box.
My budget was technically $1,200, but I did exceed that in order to get something I am proud of, and to be confident it isn't obsolete in a year.
EDIT 03/10/2015: I added a EVGA GeForce GTX 750 Ti 2GB Superclocked GPU because I was able to sell my retired 10 year old PC for almost the cost of that card. However, the heat sink on the 750 Ti was too tall and interfered with the HD. Instead, I mounted the HD in place of the front fan. This can be seen in the last picture. It's not as pretty or illuminated this way, but everything is staying cool. Plus, the GPU really rounds out the build and adds much more capability. Now I need to buy some games...