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.
I asked the same question a few months ago on a german community.
Most people advised against a SBC (RPI, …). They're not that much more energy efficient than Mini-PCs (especially with an Intel NUC or Celeron), are more modular + repairable, and use the more common x86-architecture.
You can get an used ThinClient for less than a RPI3, not even to mention a 4. This, and that you don't contribute to more E-waste, is great.
I use a Fujitsu Esprimo Q920 with an Intel i5-4590T processor, 8 gb RAM and only SSDs.
It draws about 11W under normal load, a RPI3 draws about 5-7, including hard drives, the 4 even more with the active cooling and more performant CPU.
The RPI isn't that more energy efficient, even with the enormous german energy prices, the thin client costs only a few bucks a year.
The RPI is also more prone to break, especially the SD-card.
I'm pretty happy with my current setup, would recommend.
I remember reading that thread! Well, kindly asking my half-german wife to translate it for me. It was very helpful!