The best pictures are definitely the ones in your head, but I am certainly not opposed to well-illustrated picture books for either kids or adults. I've seen some wonderful picture books. A child can benefit from either picture books or written materials, so I'd be entirely in favor of both of them...or combinations of the two. The old editions of Winnie-the-Pooh and The Wind in the Willows both had great art in them that really added to the storyline.

In fact...I think combining text with visual art is the best way to go.