A straight-forward budget oriented build. All parts were purchased from Amazon with Prime, except for the GPU from Newegg, and OS from a 3rd party wholesaler. I threw this list of parts together on a whim for a friend and I'm quite happy with the finished product. It performs well while delivering 60fps+ in most games at ultra settings. I splurged over budget with the extra RAM and M.2 storage. I feel like an SSD is almost mandatory nowadays for your OS. I'm sure some money could have been saved waiting for sales if you have the patience. I also did not utilize any mail-in rebates.
CPU: I decided to go with the Ryzen 5 2600 rather than the 3600. The main reasoning was price. The 2600 is tried and true from many builds that you see. Also using the stock cooler for now. An upgrade to a Hyper 212 may be in the future.
Motherboard: Went with a 450 chipset and love ASRock for their UEFI/BIOS. This one was modest, but has everything I needed for the build. This version also did not need a bios update, which was nice. It's inexpensive and doesn't look outrageous. I also specifically wanted a Micro ATX form factor because of the case being selected first. There was also no need for a fan splitter either due to the 2 case fan pin outs.
Memory: Searched for the cheapest 3000mhz 16gb kit available. I already went over budget selecting a 16GB kit rather than an 8GB kit, so I decided to go with 3000 rather than more expensive 3200 or 3600 kits. The heat spreaders are rather tall, but this was accommodated for by flipping the CPU fan. The RAM is also silver and matched the mobo rather well. RAM prices have fallen so much recently that I felt 16GB is well worth the extra cash.
Storage: HDD - For mass storage I went with the cheapest 2TB 7200RPM drive available. I've also used the Ultrastar drive in another build. No complaints there. SSD - For the boot drive I decided to go with an M.2 SSD because the motherboard supported it. I chose a 120GB Kingston model due to them being a reputable brand. 120GB is also plenty of room for an OS. The price/GB ratio didn't make sense below this storage capacity. It blows me away how inexpensive SSD storage is now compared to a few years ago. This SSD in particular was the cheapest I could find at the time. The speeds are comparable to a 2.5" 850 EVO SATA which is good enough. The form factor was the main decision with this purchase. Space saving was key in this case.
GPU: I was originally seeking an RX 580 or a GTX 1660. I eventually settled on this 570 due to the amazing price point that the 500 series cards are now resting in. I also chose this card because of the 8GB of VRAM. Test results and gaming have been much better than expected thus far. This card is capable of 60fps+ in most new games on ultra settings at 1080p. 1440p on high is possible as well. Some older games, like Skyrim (some mods), perform ok at 4k medium/high.
Case: The only thing I was unsure of was the case. A few 3M rubber risers on the bottom of the case can solve the intake issue that others have mentioned. I replaced the front intake fan with an LED fan to match the blue power LEDs. The cable management in the backside is a bit of a cluster. You can mitigate this by planning out your cable routing beforehand. It was difficult not blocking the already suffocated intake fan with wiring. If you buy this case, you should buy a modular power supply. There is no power supply shroud due to the case's size. The power supply is also top mounted. I'll upload more pictures when we decide to install a DVD drive. I have the power and SATA cables routed and ready for DVD drive installation at a future date. I wish the exhaust fan was at least 120mm, but you get what you pay for. The power supply is mounted upside down to assist with exhaust. It's a relatively sleek case though. Plus there's a window if you're into that. HD front audio, 2 front USB 3.0 ports, and 2 front USB 2.0 ports is a huge win for $30. This case often goes on sale for <$30. Overall, I recommend this case for this price range. Any higher tier GPUs or CPUs will need better cooling options.
Power Supply: I searched for the least expensive, modular, ~550w 80+ power supply from a reputable brand. Corsair power supplies have never failed me before. As I said before, a modular power supply is almost a requirement for this case. The writing on the power supply is also grey which works well with the mobo and RAM coloring. I mounted the power supply with the fan facing towards the CPU. Your power supply also doubles as a secondary exhaust in this case. Shout out to Corsair for making their branding inverted and reversible if you decide to mount it upside down.
OS: I didn't want a watermark, so I bought Windows 10 Pro from a 3rd party wholesaler. It's only sketchy if you think about it (don't).