I have some kind of addictions for Adafruit feather and other CircuitPython boards.
Adafruit Feather and FeatherWing board is a great ecosystem to experiment with CircuitPython and build prototypes. Some of their Feather can run CircuitPython and lot of library can be used to manage FeatherWing extension boards (sensors, screen, LED, WiFi, Bluetooth, buttons …). I have some preferences for the M4 Express. The Hallowing and PyGamer badges can also be extended with FeatherWing boards.
The CircuitPlayground are nice board to start too because it already have some sensors, led incorporated like the Hallowing and PyGamer but without the FeatherWing extensions.
If you need more power and more GPIO then the Metro M0, Metro M4 Express, Grand Central M4 Express or NeoTrellis M4 Express is a better choice.
If you need smaller board, the ItsyBitsy M4 is a really cute board. The PyRuler is fun to have too ?