My favorite author of all time is Chinua Achebe, simply because of the themes of his work and his underlining message. My favorite books of his are "Things Fall Apart" (1958), "No Longer At Ease" (1960) and "A Man of the Peoples" (1966). I'd recommend these books to any true fan of English Literature.
Okay, where do I start... one of my favorite ones is Ruth Gruber and her book Ahead of Time: My Early Years As a Foreign Correspondent. It made quite an impression on me because of so many similarities of her family history and mine. This crazy bitch decided in the middle of the thirties and right before WWII, to go travel the world and see how women live in different countries! She traveled to Stalin's USSR and pre-Nazi Germany... and made it back to the US in one piece! My other favorite author is Janusz Korczak who perished in Poland during the Holocaust. He wrote several works, I read When I'm Little Again and his ghetto diary. I also like several Russian authors whose names would probably be unfamiliar to most readers here.
Moskvichka I thought you would choose the Brotherman Alexander Pushkin. If he was a poet instead of a writer than I stand corrected.
Amina Wadud, Asma Barlas, and Sachiko Murata because they are amazing women thinkers who have extensive knowledge of history, Islam and cultural differences.
Rudyard Kipling. Another genius. I know that "If" is almost cliche now b/c everyone quotes it, but that's the mark of a truly great work. It's profound, truthful and speaks beautifully of so many absolutes. IF you can keep your head when all about you Are losing theirs and blaming it on you, If you can trust yourself when all men doubt you, But make allowance for their doubting too; If you can wait and not be tired by waiting, Or being lied about, don't deal in lies, Or being hated, don't give way to hating, And yet don't look too good, nor talk too wise: If you can dream - and not make dreams your master; If you can think - and not make thoughts your aim; If you can meet with Triumph and Disaster And treat those two impostors just the same; If you can bear to hear the truth you've spoken Twisted by knaves to make a trap for fools, Or watch the things you gave your life to, broken, And stoop and build 'em up with worn-out tools: If you can make one heap of all your winnings And risk it on one turn of pitch-and-toss, And lose, and start again at your beginnings And never breathe a word about your loss; If you can force your heart and nerve and sinew To serve your turn long after they are gone, And so hold on when there is nothing in you Except the Will which says to them: 'Hold on!' If you can talk with crowds and keep your virtue, ' Or walk with Kings - nor lose the common touch, if neither foes nor loving friends can hurt you, If all men count with you, but none too much; If you can fill the unforgiving minute With sixty seconds' worth of distance run, Yours is the Earth and everything that's in it, And - which is more - you'll be a Man, my son! If you want to see more of his work check here http://www.kipling.org.uk/