The FightBox B1 is an all-buttons controller that prides itself for being ultra thin.
The RAC-J800B, part of the J800 series, is an excellent all-buttons controller that is available in multiple variations.
Compact, thin, and lightweight, this is an all-keys controller by RetroArcadeCrafts that sports Cherry MX switches.
What initially looks like a gorgeous mini fightstick ends up being a specimen of questionable hardware.
This is a budget controller that is available in many variations and is a decent option if you would like to try hitboxes.
The NJP-308 is a mini fightstick that runs on the PC and older consoles despite coming out in the PlayStation 4 and Xbox One days.