Tip your hats and cross your hearts, lads and lasses! The MIDI Fighter Classic is the predecessor of the insanely versatile MIDI Fighter 3D and its own spinoff, the Twister. While this controller didn't have gyroscopic controls and fancy side-buttons, what made this controller stand out was its raw versatility— you could solder additional buttons/knobs into built-in ports along the side, replace any of the buttons, or even build it yourself or break it down for use in other projects.
The biggest feature of this controller is the arcade buttons, which were used because they react much faster than drum pads, keys, or plastic buttons on other controllers, and can take a lot of heavy use. They're also just plain cool. My own MIDI Fighter's buttons are starting to gunk up along the sides, but I put stickers on the tops and sides of them for a while so I only have myself to blame for this.
I haven't been able to try out the MF3D or the Twister yet, but if they're anything like the Classic (or, somehow, improvements upon it), then I heavily recommend you pick them up!