Rachmaninov wrote some suites for two pianos.Also Stravinsky 3 Easy Pieces and 5 Easy Pieces. In each case the "easy" refers only to one of the two parts: secondo for the 3EP, primo for the 5EP. Useful if you have 2 players with unequal abilities.
Anyone else?
Nikolai Medtner: Two Pieces Opus 58. There may be some audio samples at the Hyperion website played by Alexeev & Demidenko.
Glinka "Capriccio on Russian Themes (1834)Borodin "Tarantella"4hands(1862)Balakirev "Suite" (1909)Balakirev-Beethoven "Quartet Op.95" 2 piano I don't know if these are in print