That's a pretty good setup. I'll just leave my thoughts on each of the components you chose:
DISCLAIMER: This is input from just one person. Make sure you do your research!
HDD: You said you'll only play a few different games on your PC, so you probably don't need a whole lot of space. 1TB should be fine. Many people have a 2-drive setup, with their OS installed on an SSD, with other programs stored on a larger HDD. But if you don't want 2 seperate drives, getting a Hybrid Drive is a good option. (My PC currently uses a Seagate 2TB Hybrid Drive)
PSU: Glad you didn't cheap out on that! I also use a Seasonic PSU. It's always very important to get a good PSU from a reputable brand. A bad PSU can destroy your entire computer, or even cause a fire. You'll probably want to go with a modular or semi-modular one as well, since that makes cable management so much easier.
RAM: No complaints there. Almost all RAM these days is pretty much the same, and (unlike the PSU) you can usually just go with whatever is cheapest. Speed isn't too important, unless you're running an APU (Which you aren't)
Motherboard: Pretty good. Motherboard choice usually just depends on what extra features you want, like USB 3.0, UEFI BIOS, more PCI-E expansion slots, built-in RAID support, etc.
CPU: Again, a good choice. As long as its number ends with a "K" (indicating it has an unlocked multiplier, so it can be overclocked) you don't need to worry about too much. As long as it isn't an i3, since you'll want a quad-core at minimum.
GPU: Since this is a gaming PC, the GPU is pretty much the most important component alongside the CPU. Personally, I'd go for a little bit more that what you've chosen, probably an R9 285 or a GTX 960 (The latter being what I'm running).
Case: Just choose whatever looks best and fits your other parts. You may also want to keep in mind how good their cable management and airflow is.