The platform that an arcade controller works on may be a lead factor in your decision regarding whether or not to buy that controller.
What a great time to be alive! You can now get the cat-shaped Wasabi that can turn heads at a tournament and still perform at a high level.
Cubs made a hybrid, the Cubstraption, that has a GameCube controller on the left and half of a box controller on the right.
The ST is a primarily stickless controller that is made of inox steel, has a see-through bottom panel, and glows in different colors.
It seems that DOIO took its creative liberties with the spacing of the KBGM-H03's buttons, especially the uppermost button.
The Mini•Dub is a smaller version of the 4TW by jonyfraze, and the primary difference is how the edges are mostly straight.
The VM6R offers multiple layouts and can be ordered as a case or preassembled. It also features both Iris and Lolli tech.
Chibico by Acrycade Gear is a mini stickless controller that should be able to fit into a back pocket of a pair of pants.
The Hori Fighting Stick Mini is an average mini fightstick that might catch your eye in the sea of competitors.