Oh, geez. I could probably name quite a few of this category...
Debussy: Preludes, Arabesques, Valse Romantique, Reverie
Chopin: Preludes, Nocturnes, the slower Etudes
Liszt: consolations, Liebestraume
Mendelssohn: Songs Without Words
Schumann: Scenes from Childhood
Brahms: Intermezzo op. 118, no. 2, Rhapsodies op.79
Grieg: Lyric Pieces
Rachmaninoff: Elegie op. 3 no. 1, some of the preludes and etude-tableaux, Moments Musicaux
Ravel: Sonatine
Schubert: Impromptus, Moments Musicals
Mozart: All sonatas and concertos (I have to admit, I really like Mozart, hehe)
Alright, I should stop now. I picked the smaller scale pieces because they tend to get overlooked many times. Oh, and don't forget the 18th variation too.
