Get the AMD Ryzen 7 5800X for £200 (RRP £420)
I ran the 5800X myself for a while before jumping ship for Intel when 12th-gen arrived. The 5800X is a good CPU, running a little hotter than the 5600X but also delivering better performance. Its eight core, 16 thread design makes a lot of sense for a wide range of tasks, and it matches those of the current-gen consoles, and is a good match with a mid-range to high-end GPU. As previously mentioned, socket AM4 CPUs like this one also benefit from cheaper DDR4 RAM and compatible motherboards compared to Ryzen 7000, which requires more expensive DDR5 and AM5. Note that the near-identical Ryzen 7 5700X does remain more affordable, at £185, but with the prices this close either is a reasonable option. If you’re going to just install it and ignore it, then I’d go for the 5700X, but if you want to spend some time tweaking voltage curves, messing with PBO and generally wringing as much performance out of the CPU as possible, the 5800X ought to be better-binned than the 5700X and might be worth the extra cash.