CPU and MB:
The pair is illogical (i5-7500 + Z170). The Z170 motherboard is designed to support 6th-gen Skylake CPUs out-of-the-box and intended for overclocking unlocked Intel CPUs (the "K" series, such as the i5-6600K or the i7-6700K). The i5-7500 is a 7th-gen Kaby Lake CPU that is locked (non-"K"). Though that i5-7500 will still fit in the socket of the Z170, two issues will arise:
1) Performance issue. You are paying the motherboard's overclocking features you can't use. It is better to get an unlocked CPU to pair with this kind of board *or* get a non-overclocking motherboard for your locked CPU.
2) BIOS update issue. The Z170 will need a BIOS update to run a 7th-gen Kaby Lake CPU. To eliminate this incompatibility issue, you would need a 6th-gen Skylake CPU that works with the Z170 *or* replace that Z170 with a current-gen motherboard (Z270) which supports both 6th-gen and 7th-gen CPUs out-of-the-box.
The i5-7500 is one of the best in price/performance among the i5's currently available today. It is a locked CPU. Best to choose a motherboard that has a B250 chipset for price/performance pairing.
RAM: Good choice on the RAM, unless you want to save more money, you can also get an 8GB (2 x 4GB) as a minimum for most gaming requirements. If you will use this PC for multi-tasking/editing works, then your 16GB choice would be okay.
GPU: The GTX 1060 is one of the top-of-the-line GPUs for 1080p-resolution/~60fps gaming (alongside the RX 480). However, the GTX 1060 version you chose only has 3GB VRAM (which for some, may be enough for the games they play). Price/performance leans toward the RX 480 having more VRAM at 4GB for a much lesser cost. Alternatively, you can also get the GTX 1060 6GB or the RX 480 8GB versions if budget permits. But if you are looking at gaming at the 1440p-resolution (or 1080p/120Hz++), the GTX 1070 is a better choice (but more expensive). So, the GPU would be dependent on your gaming monitor's specs.
PSU: The EVGA 850W is both an overkill and a mediocre unit. A good-quality 550W would suffice for your listed rig with a single GPU (even with future upgrades on more powerful components). Consider looking at the Seasonic G-550 which is semi-modular, good quality components, and 5-year warranty. If you like EVGA, get the SuperNOVA G3 550 for fully-modular and 7-year warranty. If you can bump up the budget, the Corsair RM550x is fully-modular and has 10-year warranty. If budget is really tight, the Seasonic M12II-520 EVO is a lesser quality than the aforementioned PSUs but is fully-modular and has a 5-year warranty.
SSD and HDD: Good choices on the 250GB SSD and the 1TB HDD.
Case: Good choice (somewhat subjective, depending on your personal taste).
Hope these thoughts would help.