Graffiti on Palm handhelds. I owned the original PalmPilot and a couple of other models up to the Vx, and can still write Graffiti faster than I can type on a touch screen.
Discounting the Newton (which I tested but didn't own), there still isn't anything else that even came close in terms of practical "handwriting", and even though there's an Android keyboard that does Graffiti, ACCESS is sitting on the IP and has done nothing with it.
I'd forego a non-critical bit of my anatomy to have Graffiti on iOS with a decent stylus. Not even the MyScript keyboards come close.