The true strength of PC gaming, to me at least, is the combination of speed and precision that a mouse brings, which to my experience no joystick or thumbstick can match, and the range of motion no touch screen can cover (after all, you don't have to stop moving the mouse when the cursor is at the edge of the screen)
However, I am not satisfied with a keyboard, simply because of the digital input. I primarily play platformers and FPS, I'm sure I would say differently if I were an RTS gamer- but when I use a controller I love the ability to move faster and slower just by tilting my thumb several degrees, and being able to pick any angle of motion rather than one of 8 directions is fantastic. Unfortunately, the thumbstick I use to aim or look around tends to fall short for a task that often requires the ability to turn upwards of 180 degrees and hit a target that's often around 20 pixels tall, before the target does the same to me.
My ideal control setup would be a mouse in one hand, and a keyboard set on a 2-dimensional slider in the other- to move forward I would push the entire keyboard forward, and so on. As long as your hand remained on the keyboard the relative position of keys would remain the same so there'd be no added need to look at the keyboard to find a key after moving it. Potentially if the slider didn't have a spring one could leave it in a position while keying in commands, somewhat like an autorun, but finding the center again could then be an issue.
