Depends what you’re aiming for: 
Power efficiency?
In general I like arm. I was a bit disappointed with the rp3 but the 4th runs smoothly, so I can imagine that the 5 is doing fine. 
Other options I like are the APUs 

 rp5 is great the ram increase is very useful, especially if you're running a node  

 What I really like of the rp5 is the M.2 support that would definitely help. Though my rp4 still manages running a #bitcoin node, and a #monero one quite decently on an #OpenBSD (not exactly a fast OS). N the top of that I had it running a netatalk for #timeMachine backups but that was on the very limit. 
https://m.primal.net/KZCP.jpg 

 used laptops that have batteries & native durable storage vs adapted for USB 😉 

 I'm running out of old laptops at this point 😂 

 Not cheap, but not super pricey...

I'm running a fully loaded Start One from the Start9 people.

So far so good; small, quiet, unobtrusive...

I haven't actually measured the power draw yet, though I suspect it's pretty reasonable?