Blind Willow, Sleeping Woman (BWSW) is an amazing collection of short stories. Spanning 25 years of Murakami's career (the oldest story was originally written in 1980, while several were penned in 2005), the stories in BWSW show off Murakami's amazing skill and versatility. Murakami's stories are often described as defying typical genre classifications, and while this is true, it would be a mistake to interpret this as meaning that all Murakami stories are the same. The stories in BWSW will alternately leave you scared, laughing, amazed, and confounded. Although everyone will have their favorite stories, my personal favorites were Firefly (later expanded into Norwegian Wood), Hanalei Bay, Tony Takitani, and The Mirror. I felt the first three best represented Murakami's patented ability to tap into the tightly-linked joy, loss, and loneliness of the human condition, while the fourth was enjoyable as the pure "ghost story" ... while this genre is a staple in Japanese literature, it is a departure from the rest of Murakami's works.
If you are new to Murakami, I think that his short story collections (either BWSW or The Elephant Vanishes) are the best place to start. Murakami's works are best "felt" rather than "analyzed" and short stories are the best way to get acquainted with his talent and style. If you like his short stories, try a novel. Which one is a matter of personal taste ... interestingly, while Wind-Up Bird is typically his most popular work in the West, it is his earlier works (notably Norwegian Wood, Hard-Boiled Wonderland, and Dance, Dance, Dance) that remain even more popular in his native Japan to this day.
If you are an old Murakami hand, you might be wondering what is next. Unfortunately the future is a little murky. Murakami seems to be in the process of re-inventing himself, and the first product of the "new" Murakami is After Dark (due to be released in English in 2007), which received mixed reviews in Japan. Personally, I look forward to whatever work follows After Dark, to see which Murakami we can expect in the future. As for me, I think I'll go back and re-read his earlier works to immerse myself once again in the always amazing, always indescribable, and always unforgettable universe that is Murakami World.