The whole surround sound think, especially the final system, a Yamaha DVD player that was unreliable, Rotel Pre processer that never worked properly with volume that changed mid track lots of lights but no setting that was not awful, 2 channel power amp that was really quite superb and stayed as a stereo amp for 15 years until recently, a 5 channel power amp with no guts and 5 Kef speakers that apart from the centre, I still have but have no need for, were lumpy and disjointed.
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