For fighters its 100% original stick for me. Strangely enough I actually unscrew the ball and use the joystick as just a small rod, as it seems to be more comfortable that way. (can this get any more sexual sounding? haha
For shooters and games such as Puzzle Bobble / Puzzled , I always use the cd pad, as it just seems better suited to those games.
So I use a combo of both really