Well, I don't want to sound proud but I had won few first prizes in competitions, and the cellist and violinist did, too.
Some of the hardest pieces I played(and "overcame")
are Prokofiev Sonatas, La Campanella, Liszt Totentaz, Grieg Concerto, Rachmaninoff Etudes and Preludes, and Chopin Scherzi and Ballades.