I am sure that each of us, rightly or wrongly, have judged a book by its cover. The design on the cover is the first impression that we have about the contents of the book, the genre, and an overall impression of the quality of the book. I know that I have been influenced by the cover of a book, and that has led me to purchase or not purchase the book. This article examines some of Waterstones' book covers and looks at Penguin Books. (Penguin Book's orange and white covers have become iconic in their own right, and the company have recently run a campaign to get readers to illustrate their own books.)
The cover designs to some classic books have been re-designed and are available at Waterstones' book shop. Some of my favourite new book covers are displayed below.

The cover design range "Vintage 21" uses typography in the book's cover design. The books are printed in a solid colour, and the spine of the book is the same colour as the cover. (The covers - grabbed from the Waterstone's website - are shown below, but these images do not really do the physical book justice.) Placed together, these books are colourful and brighten up any shelf.

While you can buy some beautifully-designed books, Penguin Books offers readers the chance to buy a book with a cover that you can create yourself: http://www.penguin.co.uk/static/cs/uk/0/minisites/mypenguin/index.html
A few of the covers, designed by readers, have been uploaded to the Penguin Books website, and I have included a few of my favourites below. A gallery of covers designed by readers are available at: http://www.penguin.co.uk/static/cs/uk/0/minisites/mypenguin/gallery.html

These are gorgeous. I wish I had been aware of these before; we've just completed a collage on our wall featuring the book covers of all our favourite books and these would have looked fantastic. I love the vintage look of these covers.
Just to add, your blog is really good; really fresh and attractive.
Thank you! I really like them too, of course. I also love the idea of designing your own covers.