Ummm, I think I read the Screwtape Diaries first as a teenager, but if you aren't into Christianity it might not do anything for you. I bought A Mind Awake, which is excerpts of his collective works categorized by subject matter, and it is a dream for me, lol.
Shakespeare is my all time favorite, as well, followed closely by C.S.Lewis, an INTJ, who always challenges my subjective way of thinking, and I always get such growth, and balance out of his writings, and also Lao Tzu's.
hi leo if you don't mind, i'd like to blog your response to spailpin's question in your "ask away" thread as an anonymous quote on my personal blog (off of the forums). i just found it inspiring.