Today I offer:
Aaron Copland, Symphony No. III, Bernstein/NYPO, 1986.
This does not float around the excerpt books because it is still copyrighted, I believe. It is a very accessible piece for most involved with music, insofar that the thematic and harmonic material is easily identified and followed. The playing on this recording is fantastic, with a young(er) brass section. Warren Deck sounds fantastic.
There are many other pieces of similar nature out there. I believe the Vaughn-Williams symphonies apply here. Please feel free to contribute to create a list of music for young tuba players to listen to rather than some of the familiar (hackneyed) pieces regarding tuba.
edit for photo:

