Love old books, incunabula or otherwise? A whole collection of early Shakespeare works--hard bound and beautiful--are now all available for perusal online. You can read about the volume itself, read the text in HTML or XML, or you can look at wonderful, high-resolution photographic images of the actual volume, page-by-page.
This image is from another site. Hamlet; 1st quarto 1603; C.34.k.1; Provenance: Halliwell-Phillipps
Each of these 32 editions is a pre-1642 Shakespearean quarto of Hamlet. Hamlet was chosen as the inaugural play for the Shakespeare Quartos Archive project, but they have plans to add more in the future. A quarto is a book printing technique: a large piece of paper is printed with four pages on one side, and four pages on the other, and then folded twice to make 4 double-sided leaves of a book.
These volumes aren't incunabular, they're too late, but boy are they handsome. The pictures are really high quality. If you're planning to take a look, you're going to need a fat connection.