You could search a generic topic like "fiction books" on Amazon and scroll through what pops up. I'm sure you would get several thousand on the list, though. Maybe you could narrow it down a bit to "historical fiction" or "short stories". Good luck!
Some of the discount book catalogs, such as Hamilton's ( http://www.hamiltonbook.com/online_ca... ) show the covers on the books, along with brief descriptions. These are frequently book club editions, which might have slight differences to the editions on the street, if that would make a difference to anyone. I found them looking for discount book catalogs. It's easier to search by covers here than through Amazon.
I just went to Barnes and Nobel and looked on shelves. I like cozy mysteries, so I went their first. Saw a great cover. I would also look on Amazon's new book list, or even Goodreads recommendation list if you want something online.
I work in a library so my problem is mainly that I hear about a lot of different books before I even see them. I guess I am being too nitpicky about the "solely on the cover" aspect.
My problem is I get a lot of emails with reviews, etc and I just want to look at covers and see what jumps out at me.