I can't post a performance of Philip Sparke's Euphonium Concerto, 2nd movement in particular, but that is a wonderfully compelling piece that just grips me.
Here's another of my selections:
[youtube=425,350]http://www.youtube.com/watch?v=d1WgoSfV_Kg[/youtube]
Joaquin Rodrigo's Concierto de Aranjuez for guitar and orchestra, 2nd movement.