Best Acoustics?

Where have you listened to Classical music and was
impressed with the acoustics? The best I have heard is Hill
Auditorium - University of Michigan in Ann Arbor.

From a description of Hill Auditorium:

Carol Rose Kahn, the architect’s granddaughter recounted
that her grandfather had set out to develop a hall with perfect
acoustics. The desire was to design an auditorium that would
seat five thousand people, where they could hear from every
seat.
Being aware that only one man in the country who was pre-
eminent at that time – Hugh Tallant, Kahn wrote to ask him if it
would be possible to build an auditorium for five thousand
people, where they'd hear from every seat. Tallant responded,
but only after several months had elapsed, to the affirmative;
so Tallant designed the acoustics. The result was an
auditorium in the shape of a megaphone. The granddaughter
said: "Hill Auditorium was nearly finished when I was fourteen
or so. My father and I went out to Ann Arbor. Father stood up
in the last seat of the second balcony, and I went down on
the stage. On my word of honor, I dropped a pin and he heard
it."