Your single most significant purchase mistake?

I love McIntosh (despite all the hate they draw) and still own it, but the MC7106 I bought years ago could not leave my home fast enough. Granted, it was a 6 channel amp designed for HT, but could be bridged to the tune of 320 watts of bad sound for even more bad sound headroom. I'm not sure I would even use it for home theater.

@stereo5 , it was a Clarion years unit (production run of 1992-1998).
I'll admit that Mc has built some "duds" over the years in an attempt to chase trends, but feel they hit the mark more than they miss it. My C2300 is certainly a keeper.