Ralph Vaughan Williams – The Lark Ascending http://www.youtube.com/watch?v=ZR2JlDnT2l8 (London Philharmonic);
Fantasia on a Theme by Thomas Tallis, http://www.youtube.com/watch?v=0U6sWqfrnTs.

Erik Satie’s Gymnopedie #1 (flute), http://www.youtube.com/watch?v=hwSCc1AHjLQ
(Blood, Sweat & Tears version, Variations on a Theme by Erik Satie, http://www.youtube.com/watch?v=rrZi9CuuuCE)

Beethoven’s 7th Symphony, movement 2 (the finale of The King’s Speech when King George/Bertie rhythmically expressed his radio address), http://www.youtube.com/watch?v=mgHxmAsINDk

Sibelius’ Finlandia melody, which he composed as a protest against Russian censorship, like the Estonians’ ‘singing revolution,’ appears in several hymns.

Singing in midst of full choir, Handel’s Messiah, Bach motets in German, in Germany (e.g Jesu, meine Freude), Faure Requiem, Brahms Requiem…I also like Bach organ Fugues.
I love the soundtrack of “Impressions de France” at Epcot (http://en.wikipedia.org/wiki/Impressions_de_France, a copy starts 3 minutes into this Vimeo, http://vimeo.com/42490980):
Claude Debussy – Syrinx, Nuages from Nocturne;
Camille Saint-Saëns – “Aquarium” from Carnival of the Animals (I like the flute here, too); Symphony No.3 in C Minor (dramatic organ).

There’s always Ravel’s Bolero, http://www.youtube.com/watch?v=KK23BhEQVyU: this video shows instruments echoing each other with the famous melody. “In the mayhem that followed the premiere performance, a woman was heard shouting that Ravel was mad. When told about this, Ravel smiled and remarked that the woman had been the only one who had understood the piece.” http://en.wikipedia.org/wiki/Bol%C3%A9ro