Critical (Best) Music Tracks for Speaker and Room EQ Testing

[MediumRare]

For me it's a tough question. The most challenging tracks are those that really aren't mastered well, and sound off even on headphones.

Do you prefer a system that tries to make inadequate tracks sounds good? IMO, I’d rather have an accurate reproduction even if it’s mediocre. Then stellar tracks sound fully stellar. Otherwise they would be the ones sounding mediocre/out of balance.