I am not a visual person. In college I made a friend accompany me to the art gallery to help me figure out what I was seeing for an assignment for Art History 101. Post-college, I looked at the wordless Ikea directions with horror and confusion (not only was I confused about what to do, I was confused as to how anybody could think wordless instructions were useful) and immediately found some friends willing to help. So it was much to my surprise that I discovered that several of my favorite picture books are wordless.
Perhaps my absolute favorite wordless books (if I had to choose) are Jan Ormerod's "bookend" pair (pun intended)
Sunshine and
Moonlight. They both follow the same family (mom, dad, daughter) through the rituals of getting up in the morning and going to bed at night. Despite the fact that they focus on what can be very hectic times of day, both books convey a kind of peacefulness. I found them serendipitously at Books of Wonder, a fantastic independent children's bookstore here in New York.

All of Suzy Lee's books are amazing.
Wave tells the story of a little girl at the beach;
Mirror uses double-page spreads to turn the book into a mirror and
Shadow shows how a little girl's imagination converts the shadows of ordinary items in her attic into monsters and animals in the jungle.
Shadow also uses double-page spreads. It is a tall thin book but has to be turned horizontally to be "read." I love how the protagonist in each book plays so happily all by herself without a toy in sight.

In the Town All Year 'Round by Rotraut Susanne Berner is a more traditional wordless book, in the vein of Richard Scarry. I don't remember how I came across it originally but
Playing by the Book's recent post about a similar book,
It's Snowing in Animal Town by Hannamarie Ruohonen reminded me of it. It follows the citizens of a single town throughout the year. The book is divided into seasons and each has an introduction to some of the characters and clues about what to look for. It is very detailed and rewards rereading with new discoveries each time.
After reading
Playing by the Book's posts about "reading" wordless books to and with your children
http://www.playingbythebook.net/2011/01/05/listening-to-children-create-their-own-stories/ and
http://www.playingbythebook.net/2010/05/30/going-to-the-zoo-zoo-zoo/ I was struck by a thought: to my non-reader and not-quite-a-reader, ALL books are wordless when an adult is not there. Of course, my kids often "read" a book they have heard before using the words they have memorized or almost memorized, but they sometimes tell the story in their own words as well. Hearing how they paraphrase the text makes for great eavesdropping!