As a console interloper hailing from the PlayStation side of the tracks, I have a soft spot for controller rumble and haptics. It would appear I'm in good company, as a wild Sony patent exploring a fresh avenue for tactile feedback right there in your gamepad has just been published.
The patent in question concerns reactive buttons that can both soften and harden (via Cheat Happens). In theory, this would offer different tactile sensations by altering button hardness in real-time, depending on either the in-game situation or, ahem, personal preference (steady on).