Hello! This build's purpose is to play recent games at 1080p. It has to fit in a limited space in my desk, so it uses Mini-ITX form factor, and the budget is around 800€. Last time I built a PC was in 2007 and I was totally out of the loop, but I managed thanks to the recommendation from /r/buildapc subreddit and discord channel, and by browsing other builds on pcpartpicker.
Overall, I'm very satisfied with this PC. No heating issues, very low noise, great performance. Still have to experiment, but I managed to play World of Warcraft, Metal Gear Solid V: Ground Zeroes and the DOOM demo at maximum detail with zero issues.
I do not intend to overclock, so a 6600k didn't make much sense, and a 6600 didn't seem worth 40€ more than the 6500. Stock cooler is fine.
This motherboard has a lot of features for its price: integrated Wi-Fi, M.2 slot on the backside, B150 chipset, cool orange LEDs. Wi-Fi antenna has a magnetic base, pretty useful.
Only one 8GB stick to fit in the budget, might add one more in the future.
I went for an M.2 SSD: the less cables around the case, the better, and the price was the same as the 2,5-Inch version.
For playing at 1080p, this card is great. The maximum GPU lenght allowed by the case is 267 mm, and this one fits perfectly with 223 mm while still being a full-sized GPU. Has semi-passive cooling, so fans won't spin until the card temperature gets too high.
The limiting factor in the choice was a maximum width of 265 mm, since the case has to fit in a tight space. The SG13B is 222 mm wide, fits full-size graphic cards and has a mesh front panel. Other cases like the Cooler Master Elite 120 or 130 were interesting, but this one was smaller and more compact. It's a bit cramped inside, so cable management is almost impossible, unless custom-length cables are used.
This PSU is fully modular and comes at a good price. It's also 140 mm deep (instead of the usual 150/160 mm), so it leaves space for the upper drive cage in the case. I got a bit disappointed with it, though: the 20-pin connector doesn't plug all the way on the PSU for about 1,5 mm. Moreover, the fan gets noisy if pointed down (as in pictures, I wanted it to blow warm air outside of the case), but I had no issues with it when I pointed it up.
The case can also fit a 140 mm fan, but then there's no space for the upper drive cage, needed for mounting a 3,5" HDD. I got a 120 mm one since I might mount my old HDD in the future, the difference in airflow is negligible. This fan blows air inside the case.