I dunno, maybe I've completely missed the point in his writing, but I just tried reading "The Wisdom of Insecurity" and it seemed like almost complete nonsense to me. There were definitely a few passages that were very insightful, but the other 90% (at least to me) was incoherent rambling.
I didn't mean to recommend Alan Watts in general, though I generally like him. I just think Zen can be a bit hard to get into without some introduction and I consider Watts' decent.