If you have been a pad player for a long time, the easiest transition for you may be a controller with a D-pad on the left and arcade buttons on the right.
The Alpenmeister TE's Hall effect switches allow you to adjust the button sensitivity, and there are also D-pad buttons near the aux buttons.
Given the sweltering success of the PadBox GS, Arkodd released the Platform Edition: half a rectangle with a D-pad and analog stick.
The Pico Pad is a nifty card-sized controller for tournament organizers, whereas the Pico Pivot is specifically for Smash tournaments.
You can buy the PadBox GS preinstalled with a non-split or split D-pad, and it's good for fighting games & other genres.
The CounterHit Compact is the creation of a Seattle engineer, and its loop lets you attach the tiny CounterHit Nano controller.
Remember the banned GafroBox? Well, Gafro released LI.TERAS, which brings back the same goodness—plus interchangeable modules.
Available in preassembled & DIY formats, the PadBox is a plastic D-pad controller with Sanwa buttons, Omron switches, and custom LED.
Cubs made a hybrid, the Cubstraption, that has a GameCube controller on the left and half of a box controller on the right.