Opinion on my Gaming Build

[winternx]

What can I improve? Price max is $900-950

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 5 2600 3.4 GHz 6-Core Processor ($174.00 @ Amazon)
CPU Cooler: ARCTIC - Freezer 33 eSports ONE (Black/Red) CPU Cooler ($31.98 @ Newegg)
Motherboard: ASRock - Fatal1ty B450 GAMING K4 ATX AM4 Motherboard ($97.96 @ Newegg)
Memory: Corsair - Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 Memory ($129.99 @ Amazon)
Storage: ADATA - XPG SX6000 128 GB M.2-2280 Solid State Drive
Storage: Western Digital - Caviar Blue 1 TB 3.5" 7200RPM Internal Hard Drive ($44.85 @ OutletPC)
Video Card: Sapphire - Radeon RX 580 8 GB PULSE Video Card ($239.99 @ Newegg)
Case: Deepcool - TESSERACT BF ATX Mid Tower Case ($40.98 @ Newegg)
Power Supply: SeaSonic - 520 W 80+ Bronze Certified Fully-Modular ATX Power Supply ($34.99 @ Newegg)
Total: $794.74
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-11-30 07:15 EST-0500

 

[RARRAF]

I would say that PSU needs to be improved for that GPU

 

[Shektron]

What can I improve? Price max is $900-950

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 5 2600 3.4 GHz 6-Core Processor ($174.00 @ Amazon)
CPU Cooler: ARCTIC - Freezer 33 eSports ONE (Black/Red) CPU Cooler ($31.98 @ Newegg)
Motherboard: ASRock - Fatal1ty B450 GAMING K4 ATX AM4 Motherboard ($97.96 @ Newegg)
Memory: Corsair - Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 Memory ($129.99 @ Amazon)
Storage: ADATA - XPG SX6000 128 GB M.2-2280 Solid State Drive
Storage: Western Digital - Caviar Blue 1 TB 3.5" 7200RPM Internal Hard Drive ($44.85 @ OutletPC)
Video Card: Sapphire - Radeon RX 580 8 GB PULSE Video Card ($239.99 @ Newegg)
Case: Deepcool - TESSERACT BF ATX Mid Tower Case ($40.98 @ Newegg)
Power Supply: SeaSonic - 520 W 80+ Bronze Certified Fully-Modular ATX Power Supply ($34.99 @ Newegg)
Total: $794.74
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-11-30 07:15 EST-0500

Don't really need the CPU cooler, instead buy the Ryzen 5 2600X which comes with a very capable stock cooler, other than that it looks okay, motherboard can be cheaper as well - ASRock B450 Pro4 is a good and cheap board, you can go for better case or power supply with the extra budget, and also more SSD storage:

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 5 2600X 3.6 GHz 6-Core Processor ($219.99 @ B&H)
Motherboard: ASRock - B450 Pro4 ATX AM4 Motherboard ($87.71 @ Newegg)
Memory: Corsair - Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 Memory ($129.99 @ Amazon)
Storage: Crucial - MX500 250 GB M.2-2280 Solid State Drive ($52.89 @ OutletPC)
Storage: Western Digital - Caviar Blue 1 TB 3.5" 7200RPM Internal Hard Drive ($44.85 @ OutletPC)
Video Card: Sapphire - Radeon RX 580 8 GB PULSE Video Card ($239.99 @ Newegg)
Case: Deepcool - TESSERACT BF ATX Mid Tower Case ($40.98 @ Newegg)
Power Supply: Corsair - CXM 550 W 80+ Bronze Certified Semi-Modular ATX Power Supply ($49.99 @ Newegg)
Total: $866.39
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-11-30 07:37 EST-0500

 

[King Dranzer]

Here is the list:

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 5 2600 3.4 GHz 6-Core Processor ($174.00 @ Amazon)
Motherboard: Gigabyte - B450M DS3H Micro ATX AM4 Motherboard ($54.99 @ Newegg Business)
Memory: G.Skill - Aegis 16 GB (2 x 8 GB) DDR4-3000 Memory ($99.99 @ Newegg)
Storage: Gigabyte - UD PRO 512 GB 2.5" Solid State Drive ($59.99 @ Newegg)
Video Card: Sapphire - Radeon RX VEGA 64 8 GB Video Card ($439.99 @ Newegg)
Case: Corsair - 270R ATX Mid Tower Case ($49.99 @ Newegg)
Power Supply: Corsair - RMx (2018) 850 W 80+ Gold Certified Fully-Modular ATX Power Supply ($79.99 @ Newegg)
Total: $958.94
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-11-30 09:45 EST-0500

Way more powerful Vega 64 around 50% more powerful than RX 580. In your budget. All high quality components.