Edgar Allan Poe is undeniably one of the all time best writers of American Literature, and also one of the best writers of all time. In addition his writings are some of the most popular throughout the world despite the somewhat lack of their popularity during his own lifetime. Had he lived a longer and fuller life, had he written more of his maudlin yet haunting poetry, more of his macabre frightening yet intriguing short stories, another novella or two filled with the fantastic, and had he continued with his then unique literary creation and written more modern detective stories, he would likely have gone down in history as a writer unparalleled in his magnificence, or at least as the greatest American writer of all time. Regardless of his short pained life - he died when only 39 - and regardless of his shorter literary life, Poe indeed achieved a greatness with pen that few have ever matched. Be I so bold to say what I am about to, I believe he would have achieved the same greatness as Shakespeare, who died probably a few days short of 52, had he lived and written as long. (Heck I just surpassed old Will in age.)
Poe was a masterful user of the English language, and some others for that matter such as Latin and French. If you have never read any of his work, I suggest you give a few of them a try. Some of my favorites have been:
To --- (the one that begins with the words "I heed not...")
The Cask of AmontilladoThe Murders in The Rue Morgue
The Mystery of Marie Roget
The Purloined Letter
The Pit and the Pendulum
There are many, many others. Besides short stories and poetry he wrote journalistic essays, articles, and one novella or short novel: The Narrative of Arthur Gordon Pym of Nantucket (another great one, but not all that easy to read as it is heavily laden with mystic symbolism).
Poe was misunderstood during his lifetime, and was even more so after his death. Most believe him to have been a half depraved drug addict, but much of that belief was based upon a libelous biography written after his death by Rufus Griswold, a man who despised Poe and who let his hatred of him carry on even after Poe's passing.
If you would like to learn more about Edgar Allan Poe, things that even up until a few years ago had not yet come to light (such as the fact that he was not a drug addict) you can find more info on Poe at these links:
The House of Usher: http://www.houseofusher.net/
Project Gutenburg: http://www.gutenberg.org/browse/authors/p (page down to Poe)
No matter what you think of him or his life, no matter what you think about his works, he was and remains one of the most influential writers of all time. As in the Raven with thoughts of 'lost Lenore', Poe will never be with us again but so too shall his shadow, cast upon the literary floor, leave us Nevermore.
All the best,