It specifically depends on how much you wish to spend on a quality GPU. By quality I mean ASUS or MSI. Avoid XFX even though they appear to have high end cards for less, spend the little bit extra for better products. As far as Nvidia or AMD they are both equally good. Use common sense when comparing the reviews, I have AMD cards in all of my desktops but don't let that let you think that Nvidia is an inferior card by any means, in some test they out perform AMD and vice-versa.
It mainly depends on your motherboard PCIe ports. Observe the specs of your motherboard for the PCIe GEN. Tese will read as PCIe Express 3.0 x16 or PCI Express 4.0 x16. Now even the B350 series boards support the PCIE 3.0 x16 standard. Just make sure you install the card in the highest performing PCIE slot. Look at your board manual and it will show you which one that is, usually the first one next to the CPU socket. Another issue where this is significant is with an NVMe SSD. Read the motherboard manual.
Now go to Newegg.com and enter graphics card in the search or use their menu selection. They will have what you need with probably the lowest prices you will find them anywhere. Again Nvidia Geforce or AMD Radeon either is fine. Look at the specs on these graphics cards, some of them require the PCIE 4.0 slots. So if your motherboard doesn't support that keep looking. Although I do believe all of the latest cards are PCIE 4.0, so if your board only has a PCIE 3.0 slot it should be backward compatible.
I hope this helps you make a good choice, so happy hunting and please don't do what I saw someone once do and try to install AMD Radeon drivers for an Nvidia GeForce card, they won't work.
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