When speaking of forgotten genocides, it would be a colossal oversight and horrible injustice to omit the suffering of the Armenians. In 1915, under the pretext of preventing "rebellion" in areas bordering tsarist Russia, the Ottoman Empire deported Armenians en masse from their historical homeland, killing anywhere from 800,000 to 1.5 million in the process.
This was the first real genocide of the 20th century, and its success - the Ottomans were never called to account, and the Ataturk government that replaced them finished the job by ethnically cleansing the Greeks - inspired others. Adolf Hitler reportedly quipped, "Who, after all, speaks today of the annihilation of Armenians?" Thanks to Ankara's efforts to suppress any inquiry, and Turkey's strategic value as American ally during the Cold War, few speak of it even today.
For more information, see Gary North's excellent article today on LewRockwell.com. And remember the Armenians.