We all feel touched when we open up a good transliteration of the Qur'an and we ponder and wonder at the beauty of the words and the deep meanings within. But in reality we are just seeing a glimpse of the real treasure that the Quran is.
Imagine how you'd feel if you could understand the words of Allah Ta'ala in the form in which they were sent down and not just rely on a transliteration in English. Arabic is a language of words with precise, unquestionable meanings as well multiple nuances.
Indeed, it is a language which can, in only a few words, address a very specific topic (e.g. Laws of Inheritance) as well as convey diverse meanings (e.g. As-Samad, one of the names of Allah Ta'ala cannot be translated into just one word; it can mean the Absolute, the eternally Besought of all, etc.)
Classical Arabic has consistent, predictable rules of grammar, pronunciation, and spelling; making it actually a fairly easy language to learn. It is a poetic language, pleasant to the ear. The mere sound of the Quran being read in Arabic has been able to move even non-Muslims to tears! Subhan-Allah (Glorified is Allah), what a beautiful medium Allah Ta'ala chose to guide us, teach us, and comfort us with.