to go slightly further and name machine models, here are some I've been enjoying,
ARM
- Pine64 "Rock64" (note: this is not the same as "Rock Pi"). Fast, fairly smooth bringup. although it has a strange HDMI output glitch during heavy RAM congestion that has to be fixed with a uboot recompile
- Orange Pi Zero LTS. tiiiiiny!! runs Armbian okay. The i2c bus is locked to 400khz. Runs a little hot, so recommend a fan. and compounding that issue, the onboard SoM temperature sensor is faulty
x86
- Dell/Wyse 5070 thin client. A little large. Decently fast, costs like $75. has SODIMM slots and one SATA NVMe, no i2c/spi available but there are USB or HDMI/DP/DVI versions of most things you'd need, and an Arduino's easy to add too for gpio. works perfectly with mainline Ubuntu
- Dell/Wyse 3040. Ditto above caveats. No onboard SATA ports or RAM slots. Closer to Pi dimensions, works perfectly w/ Ubuntu.
- Atomic Pi. Has some GPIOs, unlike the thin clients. 16GB eMMC onboard. they caught a lot of flack for rebranding surplus SBCs as a new "pi" and they need a dumb adapter for DC-in, but also 100% Ubuntu.
less recommended...
- the other Orange Pis are all over the place and they are pretty poorly documented in my somewhat-limited experience.
- I have been getting up to speed on BeagleBones and boy howdy in 2023 the docs are a mess. Kind of a shame from TI.
- I loved the Next Thing C.H.I.P. but the company is long dead and the third-party firmware tools are a little tricksy. but it does have onboard LiPo management. also there is no HDMI, only composite, unless you add a "DIP" (think HAT). Very slow too, think Pi 1B performance. but they're cute and easily snuck inside projects.