Pieces for two pianos?

[dnephi]

Only ones that I know of so far are Carmen Variations and Rachmaninoff Symphonic suites i think.

[nicco]

There are many

Here are a few suggestions

Arthur Benjamin Jamaican Rumba (pno duet)
Debussy - Afternoon of a Faun
Debussy - En Blanc et Noir (2 Piano's)
Debussy - Six Épigraphes Antiques (2 Piano's)
Franck - Les Djinns (2 Piano Reduction)
Lutoslawskis Paganini Variations for Two Pianos
Milhaud - Scaramouche for two pianos
Poulenc l'Embarquement 2 pianos

[gymnopedist]

The 'six epigraphes antiques' are for piano duet.

Other things by Debussy:
Danse sacrée et danse profane
La mer
Ecossaise (duet)
Lindaraja

Ravel has written some neat stuff as well:
Frontispice
La valse
Sites Auriculaires (duet)
Rapsodie espagnole (duet)