He never recorded an album, per se, so if you're going to go with a classical recording, you'd need to specify the piece and orchestra - and unless the orchestra is obviously way better than the majority of professional orchestras around the world (unlikely), it's hard to be able to tell the difference.
Besides, since when did Mozart hold the monopoly on greatness. Although I'll admit that I rarely listen to classical music, I've heard enough to say that I personally prefer Beethoven.
So...the best CLASSICAL recording I've ever heard is the Minnesota Orchestra's most recent recording of Beethoven's 5th.