Best-looking book cover??

I wanna find out what makes a book cover good. Something you'd pick up from a shelf without having any knowledge about. The kind of book you wanna bring out in public and leave it face up so people can see what you're reading and think "that person probably has a really good taste in books."

So what makes a book cover pretty??

To make it simpler can you guys attach a link to the image, thanks 🙂