Which piano piece should I do?

As much as I love the Gershwin, EVERYBODY and their grandmother plays it. You don't want the judges to yawn. The Elegie is not performed as frequently, and well played, will make a GREAT impression. But what is your Chopin piece? Because there may not be enough contrast here. Although Rachmaninoff is twentieth century (he died in 1943) his music is deeply rooted in the past, Chopin in particular.