For those who are fans of space photography (stars, planets and everything in between) the Hubble space telescope has long been a mainstay for images of high clarity.
Now you can see every Hubble image ever taken at Hubblesite's gallery. It's an amazing collection of photographs and composite images from the earliest days of the project until the present. Here are just a few of the thousands of pictures available there. Click on each one to be taken to its Hubblesite page.
There are many more at the link. All can be downloaded in various sizes, many big enough to be desktop wallpaper. Highly recommended.