I think the absolute worst QTE I have encountered was the torture sequence in Metal Gear: Peace Walker. None of the other Metal Gears had a torture sequence this difficult. You have to mash the A button so damn hard and for so damn long that its ridiculous. Well maybe in Metal Gear 1 but you had the option to just give in and get the bad ending. Peace Walker doesn't give you that option even, it just kills you and sends you back to the beginning of the cutscene. For a stealth game to stonewall all your progress until you become a master button masher is stupid.