You should have included a "compact digicam" category which must contain most of the worst cameras ever made 😀
My share of pain:
Minolta S404: extremely good IQ at base ISO, thanks to a great lens, natural processing and very low JPEG compression (4Mp images gave 5Mb files), but with two fatal flaws: extremely unreliable AF (would often lock in front or behind the subject, even if the subject filled the AF area), and mode dial too loose, meaning that the camera would often turn itself on in a bag, resulting in the telescoping lens being blocked and the camera locking up.
Kyocera SL300R: loved the idea of a tiny, twist-body digicam but IQ was closer to webcam grade and battery life appalling (1h or a dozen shot, whichever happened first).
Canon IXUS 800IS (aka SD700IS): great little digicam, if only its lens had been properly centered. Bottom 1/3rd was way too soft. Sent it to Canon for repair under warranty, came back unchanged with "within specs" note. Could not be returned.:bang: Gave it away to the kids...