It is difficult to choose; but Gladiolus Rag may be my favourite of all Scott Joplin's pieces - and this performance by Rifkin is just wonderful.
If you really want to appreciate Joplin, and his unique mood combinations of wistfulness with joy, you need to listen with attention.
Gladiolus follows the usual structure of Joplin's rags; which is that there are four themes - each of them repeated. The first theme also returns once (without a repeat) after the second theme and repeat. So we get: AABBACCDD.
Joplin's best work always has an integrated and overarching mood structure. In this case, Gladiolus has a generally sweet, quiet, lyrical mood; and the bass line tends to wander unusually, compared with the typically solid bass-chord alternations of most ragtime.
(The usual syncopation of ragtime is between a marching 4/4 in the bass throughout, against the 'ragged' syncopated triplets in the treble - like Maple Leaf Rag, or The Entertainer. But here the solid and typical ragtime marching feel is held-back until the end.)
The emotional climax of Gladiolus comes in the third theme, which becomes complex in terms of harmony and syncopations, building up-and-up over an (it seems) endlessly descending bass...
And then the piece ends with a simple forthright theme, as simple in essence as Maple Leaf Rag - yet, in its context, and with its subtly lyrical colourations of the harmony; there is a kind of bursting happiness that is, somehow, also aware of its own fragility.
Such is the genius of Joplin.