AMD's Ryzen 9 5900X takes pole position in our roundup of the best gaming CPUs, the only real downside being the price (especially since it doesn't come with a bundled cooler). Now that it's more widely available, though, it's prone discounted pricing. To wit, you can buy one today for $494.99 from Antonline (through the retailer's eBay account).
That's a good chunk below its $549 MSRP. It's even $5 below Micro Center's asking price, which is notable because Micro Center typically undercuts the competition with the caveat being you need to live near one of its retail locations. If you do, and you also need a motherboard, that's still your best bet—you can save an additional $20 when bundling the CPU with an eligible mobo. Otherwise, this is the lowest price around.
The 5900X is a stout slice of silicon. Underneath the hood sit 12 cores and 24 threads to hammer away at multi-threaded workloads. At stock settings, it runs at 3.7GHz (base) to 4.8GHz (max boost). It also wields a generous 64MB of L3 cache and PCI Express 4.0 support, the latter of which is a trait of AMD's Zen 3 architecture.
Only one other Zen 3 processor chip sits in front of the 5900X, that being the 16-core/32-thread Ryzen 9 5950X. That will run you about $250 more than this deal, however, savings that you could apply elsewhere (like a GPU, if you can ever find one in stock).
There's no such thing as true future-proofing, but this one of those CPUs that will last a long time before feeling long in the tooth. I'd suggest pairing it with an X570 motherboard and a PCIe 4.0 SSD, and realistically whatever GPU you can get your hands on.
