Don't let others decide for you. Decide yourself. After all, you know yourself more than we know you.
But, since I'm here, I'll give you suggestions. Just because they're not Grade 5 doesn't mean you can't play them, because the suggestions I'll give you are probably not Grade 5:
-Beethoven Fur Elise (1800)
-Beethoven Rondo Op.129
-Beethoven Sonata Op.2 No.1
-Beethoven Sonata Op.7
-Beethoven Sonata Op.14 No.1
-Beethoven Sonata Op.26
-Beethoven Sonata Op.31 No.2
-Beethoven Sonata Op.57
-Beethoven Sonata Op.78
-Beethoven Sonata Op.81a
-Beethoven Sonata Op.106
-Beethoven Sonata Op.110
-Beethoven Sonata Op.111
-Chopin Allegro de Concert Op.46
-Chopin Ballade Op.47
-Chopin Berceuse Op.57
-Chopin Etude Op.10 No.3
-Chopin Etude Op.10 No.6
-Chopin Etude Op.10 No.9
-Chopin Etude Op.10 No.11
-Chopin Etude Op.25 No.3
-Chopin Etude Op.25 No.7
-Chopin Etude Op.25 No.10
-Chopin Etude in f minor (1839)
-Chopin Impromptu Op.29
-Chopin Impromptu in c# minor (1834)
-Chopin Mazurka Op.6 No.1
-Chopin Mazurka Op.7 No.4
-Chopin Mazurka Op.33 No.1
-Chopin Mazurka Op.50 No.2
-Chopin Mazurka Op.56 No.3
-Chopin Mazurka Op.63 No.3
-Chopin Mazurka Op.68 No.2
-Chopin Mazurka in D Major (1832)
-Chopin Nocturne Op.9 No.1
-Chopin Nocturne Op.37 No.1
-Chopin Nocturne Op.48 No.2
-Chopin Nocturne Op.62 No.2
-Chopin Nocturne Oubliee in c# minor (?)
-Chopin Prelude Op.28 No.1
-Chopin Prelude Op.28 No.6
-Chopin Prelude Op.28 No.8
-Chopin Prelude Op.28 No.11
-Chopin Prelude Op.28 No.15
-Chopin Prelude Op.28 No.17
-Chopin Prelude Op.28 No.21
-Chopin Prelude Op.45
-Chopin Polonaise Op.22
-Chopin Polonaise Op.26 No.1
-Chopin Polonaise Op.40 No.2
-Chopin Polonaise Op.53
-Chopin Polonaise Op.71 No.1
-Chopin Polonaise in g minor (1817)
-Chopin Polonaise in bb minor (1826)
-Chopin Rondo Op.1
-Chopin Rondo Op.16
-Chopin Scherzo Op.20
-Chopin Scherzo Op.31
-Chopin Sonata Op.4 Allegro
-Chopin Sonata Op.35 Dopplio Movemento
-Chopin Sonata Op.58 Allegro Masteso
-Chopin Tarantella Op.43
-Chopin Variations Op.12
-Chopin Waltz Op.18
-Chopin Waltz Op.33 No.2
-Chopin Waltz Op.64 No.1
-Chopin Waltz Op.64 No.3
-Chopin Waltz Op.69 No.2
-Chopin Waltz Op.70 No.1
-Chopin Waltz in e minor (1830)
-Chopin Waltz in a minor (1841)
-Mozart Fantasy K 397
-Mozart Fantasy K 475
-Mozart Rondo K 485
-Mozart Sonata K 284
-Mozart Sonata K 309
-Mozart Sonata K 332
-Mozart Sonata K 457
-Mozart Sonata K 570
These are far from grade 5, but these are among my favorite works, and you'll probably like them as you venture into Grade 7 and 8. Sorry I didn't really answer your question much.