To demonstrate that any instrument beyond piano is strictly unnecessary, though I'll toss in a bit of colour and movement from inferior instruments to show how broadminded I am:
Rachmaninoff: Prelude in G minor Op. 23 No. 5 (hard to choose just one of these, but here is the entirety of Russian history compressed into about 4 minutes ...)
Debussy: Preludes Livre 1 No, 10 - La Cathédrale Engoulitie (o course if I'd chosen Rachmaninoff Op. 3 No. 2 I'd hae gone with something other than this)
Liszt: Hungarian Rhapsody No. 15 (or No. 2 if you've not heard it before)
Schubert/Liszt (is this cheating?): Vier Geistliche Lieder S 562 - Litanei "Auf Das Fest Aller, Seelen"
Chopin: Polonaise No. 6 Op. 53
Kabeláč: Prelude Op. 30 No. 1, no, wait, No. 5, because I couldn't squeeze in any Chopin nocturnes
Beethoven: hmmmm, better think a bit more about this
Franck: Prelude, Choral et Fugue
Grieg: Piano Concerto Op. 16 (of course later on we shall scoff at anything so common as an uncommon gift for melody. This could as easily have been Tchaikovsky)
... which brings us back to the Beethoven problem. It seems to be out of sonatas Nos. 8, 14, 21 and 23. I'll go for No. 14. Because everyone has heard the first movement somewhere along the line. And whilst the new listener is lying back feeling that they've got a hold of this classical thing at its close, the short second movement perhaps passing unnoticed, there is, as we know, that moment of "But wait! There's more ..."
And we'll finish with
Bach: Prelude & Fugue in B flat minor BWV 867