It took 90 years to translate the Akkadian, the language of the ancient Mesopotamia, but in 2011, scholars at the University of Chicago finally published a 21 volume dictionary of Akkadian, the language used in ancient Mesopotamia. Unspoken for 2,000 years, Akkadian was preserved on clay tablets and in stone inscriptions until scholars deciphered it during the last two centuries. You could buy the 21 volume dictionary for over $1000 or you can get the PDFs for free at https://oi.uchicago.edu/research/publications/assyrian-dictionary-oriental-institute-university-chicago-cad
Thanks to their efforts you can now listen to the Epic of Gilgamesh and other works of ancient Mesopotamia in the Akkadian at http://www.openculture.com/2010/10/the_sounds_of_ancient_mesopotamia.html