I am also less than enthused about rankings, but certainly Arrau is one
of the giants of this century.  I remember attending the same concert that
Dan did (although I was not 16 years old!), and had similar reactions.  I
remember the unusually conservative tempo in the Beethoven (customary with
Arrau, I believe, although I remember the Liszt being full of sweep, power,
and depth, with rather brisk tempi), and so well-crafted, sincere, and full
of conviction, with a fine sense of line and architecture.  Dan's memory is
better than mine for the details I'm sure, but it was a memorable event for
me as well.

There is a small website devoted to his legacy:

   http://www.princeton.edu/~gpmenos/table_of_contents.html

Dick Hihn