A Cambridge Audio EVO 150. I liked the way it sounded and I liked the understated appearance and compact form factor, but the streaming software (StreamMagic) interface was irredeemably awful. I couldn't live with it and I was able to persuade the dealer to take it back and I went back to using NAD/Bluesound.
Your single most significant purchase mistake?
Your most significant regret for having bought? Big expectations and an even bigger letdown? The one you kicked yourself the hardest for ever having bight