I like the Splitfish philosophy. Not everyone wants a dogbone-shaped controller or likes the way the buttons are laid out — personally I’ve never much liked the Dual Shock setup. I’m not saying the Splitfish is the thing for me exactly, but I appreciate having options. The latest, the Dual SFX Evolution, departs from the normal button layout quite a bit: the regular thumb buttons are organized in an arc around the analog stick. Bad for platformers, but possibly good for others (they say Madden and LittleBigPlanet – sure, why not?).
There are accelerometers in both pieces, and you can actually assign them to mimic the analog stick signal if I understand correctly, which is pretty cool. There’s also a button for the “flick the wrist” motion, which is probably used for throwing enemies off your back or something. Kind of cheating, but we knew it’d happen eventually.
There’s also a wireless version of the FragFX v2 controller, a mouse-based alternative to the analog sticks.