A WASD controller often has a combination of WASD keys on the left and arcade buttons on the right. Of course, there can be other variations as well.
One of the ways in which the Haute42 R16 is different than its predecessors is the inclusion of a leftmost button for your pinky.
The LVL is a leverless controller with a hot swappable PCB as well as a built-in slot for an adapter to enhance compatibility options.
The TIKITAKA T16 is a stickless controller with 16 buttons, and its dual layout allows you to use it as a WASD controller as well.
Panda Fighting offers a variety of all-button controllers in different layouts and sizes, such as this controller that has 16 buttons.
The Haute42 M16 Plus is an elegant leverless controller with a metal body, large buttons, and dual layout.
The Granola Summit is an open source PLA Pro controller that has a port for additional console compatibility.
The KBGM-H04 is a dual layout controller with an aluminum alloy top and acrylic bottom. You can also add an extender for your wrists.
Just when you thought the T16 could not get any better, Haute42 gave us the T16-C with fast Crystal switches.