The Varmilo FK2 is a 14 button controller that also comes in differently colored Sea Melody and Sakura editions.
The Mu-1612 is a 15 button stickless controller made of aluminum, and it features a split PCB layout for modular upgrades.
The SLTE is 3D printed, and metal is involved as well, but perhaps its best feature is an optional carriage handle or wire loop on its right.
The FS-MINI by Tbox is a mini controller that is available in lever and leverless editions. It can also come in preassembled or DIY formats.
You can choose the color of the small & light KBGM-H06M, which also features LED for its buttons and midsection.
The Mayflash F700 Elite is a wireless arcade stick with Sanwa parts, customizable art, and many compatibility options.
The KBGM-H08 has Sanwa parts, and it allows you to pick the colors of its joystick, buttons, top, and bottom.
The LightFox (or Light Fighting Box) is a feature-packed mini leverless controller that refreshingly comes with optical switches.