There is no single best language. Pali is a derivative of Sanskrit as Spanish is to Latin, and no one can say which is better. Rather, anyone can say which is better, but no one may believe them.
Language is ecological. Pali was the perfect language for a particular place and time, just as Spanish, or Cherokee, or Zulu. The old indigenous cultures will tell you that the place speaks the language, and the people listen, and learn it from the land. The knowledge of these ancient languages, and their revival, is the story of Elves, and Dwarves, and faeries, and dragons, and ancient ones.
One may say, then, that while there is absolute truth, it cannot be expressed in any language, for all language is only relatively true, true for a particular time and place.
Absolute truth can be approximated through language, however, and doing so in a way that is understood is the nature of the Logos. To reach the absolute using a relative language is the task of the Logos, the Way.