GrimSleeper, 2 years ago

ESP32 or Raspberry Pico, if you want something easy to use, reasonably feature full, easy to interface, inexpensive, and medium form factor.

ATTiny, if you are strapped for physical space and don't have anything super complicated to interface with. Also, really inexpensive. I like it for basic electronics projects where even a Pico would be overkill.

On the other extreme, if you need more complex software, then a Raspberry Pi Zero 2 is a great option. Fortunately, the supply situation for Raspberry Pi has been improving a bit, at last. Sometimes, it's nice to be able to use all sorts of high-level software libraries, and then you hit a limit with the ESP32s and Picos of this world.

You can also mix and match. A PiZero talking to a Pico is a great combo. A ESP32 and an ATTiny can also sometimes turn out to be the more pragmatic choice.

Oh, and if you need even more oomph, then I really like the Raspberry CM4. Lots of nice carrier boards to choose from. But that's really not a microcontroller, so might not fit OP's question.

There are plenty of other boards out there. But they frequently have poor support, or are released only for the vendor to immediately abandon them. Maybe fine for one-off projects, but I generally prefer to stick with designs that last for a couple of years. Much easier to support, if I need to revisit my project down the line.