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.
If there's a most innovative award, the JTechWorkshop would definitely be a contender. Its leverless controllers have highly custom layouts.
The Punk Workshop Leverless U provides a plethora of features, such as slimness, many layouts, different colors, and custom art.
The T series of Haute42 controllers comes in 16 or 13 button versions to suit your fighting game preferences.
The G series of Haute42 controllers can come in 16, 13, or 12 button editions in order to cater to your needs.
Perhaps the most interesting aspect about the Sunga G1 stickless controller is that it has five more buttons than what we are used to.
When not making wooden accessories for tech, StepUpSFF makes stuff like the Retro Lever-less Arcade Controller (also in WASD format).
The FightingBox Mini WASD controller allows you to choose the colors of its keycaps and switches as well as its LED settings.
The VB1 is a project by Golden Lever that serves the customer base that is interested in WASD fighting game controllers and more.