Aha! "Nimrod" by Edward Elgar is the best of the Enigma Variations. :D
Is Yanni considred classical? Modern classical?
I'd say so. :)
But how can you make classical into MODERN?
Depending on how the piece is played (e.g. modern ways of playing instruments like using the back of a bow to play a string instrument ets etc), wether theres lots of styles from different musical era's 'borrowed' and there's usually less emphasis on what key the piece is written in. Of course I'm generalising but most of music is generalised today.
I personally like The Hebrides (by Mendolssohn, I believe). Also, not a symphony, but I like Praeludium and Allegro by Kreisler (forgive my spelling).