This has been a collection of purchases rather than a single one, but it's been a nice project to keep me sane not seeing my partner during lockdown.
I got bored, had a project itch. So I thought I'd go back in time; to the late 90s/early 00s and build myself this:

Case is new, but getting an old style in decent condition for a decent price right now is damn near impossible.
Rest of the system:
CPU: AMD Athlon XP 2800+
Motherboard: Gigabyte 7VT600-P-RZ, VIA KT600, Socket A/462
RAM: 3GiB DDR 400MHz
GPU: Sapphire Radeon 7000 AGP 64MiB
PSU: SeaSonic SS-500ET 500W
For anyone who didn't see, WYP did me a massive favour by 3D Printing new mounts for the CPU Cooler so I can now mount any 80mm fan to it.
Floppy drive works great, managed to get 100 good disks plus holder for a good price. DVD drive is IDE, and that was a nightmare to find on its own; even sourced an old Logitech PS/2 Mouse and Keyboard just for it as well.
It's not done yet. I'm trying to get a Radeon X850 AGP card for it but they are like gold dust. I did consider getting a GeForce 6000 but allegedly there is a bug that causes them to crash when paired with an Athlon XP and a VIA chipset which I don't have time or money to look into.
PiTV 1.2 is my next project once I can get a suitable TV to use as a base.