Something small and 2 or 4 GB RAM. Raspberry pi's compute power is good enough for me, I'm not doing anything too intensive.
Is raspberry pi 4 still the best answer?
I am a tinkerer and don't mind tinkering. I typically use Gentoo Linux as main OS. I also don't mind ARM or other architectures. I've been eyeing the RockPro64 as well.
While the RockPro64 is great if you are looking for something ARM based, I will recommend the x64 based Odroid H3(+).
Mine has an nvme as OS drive and 2 sata SSDs as storage drives. It idles below 10W and uses like 15W under load.
Can recommend.
H3+: https://www.hardkernel.com/shop/odroid-h3-plus/
H3: https://www.hardkernel.com/shop/odroid-h3/ (what I have)