While similar to built-in bookshelves, recessed shelves seem to create a slightly different look.  Painted black, these create depth and drama in this gorgeous room with its perfect mix of mod and vintage pieces.  (Andina and Tapia Ponerl Chispa's home via Nuevo Estilo.)

Here  they also add one more layer of interest in Christine d’Ornano's home featured in Elle Decor via My White Room here

Here extra space between the studs transforms this wall.  Via Rosemary at the wonderful blog  Content in a Cottage.
I have built-ins but not recessed shelving here at my house.  Do you have any recessed shelving in your home?