Not sure you can say the Playstation controller was “impossible to improve”:

1995:
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1997: (Dual Analog, no rumble)
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1997: (Dualshock):
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2000: (Dualshock 2):
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2006: (SIXAXIS - Sony lost a rumble lawsuit and removed rumble as a feature):
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2007: (Dualshock 3 - Rumble lawsuit settled):
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2013: (Dualshock 4):
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2020: (Dualsense)
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2023: (Dualsense Edge):
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