Back in time I thought it's just some box to put in your hardware but I learned that this part is one of your most essential parts you want to consider. It's so important for:

• Convenient and clean cabling
• Cooling (!)

Fractal design is usually a very good choice

Make sure it fits your

• VESA standard of the mainboard you chose
• Dimensions of the GPU + fans (if it does not come with the case)
• needs (HDD slots, DVD/BlueRay/... slots, ...)

• BeQuiet! usually good for fans (and super quiet ;-) )

• AMD Ryzen CPUs tend to run hotter
• Usually better value
• Sockets change less and chance to upgrade without replacing your mainboard is higher

• Usually pricier
• Often use P (power) and E (efficiency (for energy saving (usually assigned to background processes/OS))) cores; if you need many powerful cores pay attention here

• Noctua is usually a good choice
• BeQuiet! usually good for fans

• Single Rail vs. multi rail (OC switch/jumper)