If you want your bookshelf design to be unique, try picking three of staggered heights. Be sure to organize the books in the same manner to tie the look together.
I like to stack my books in a scattered pattern. Stack some sideways and some right side up. Its a beautiful visual appeal. Also - use some shelves to display personal memorabilia to give your bookshelf that personalize touch
Well a unique design would be something slanting. They usually have straight up book shelves. I'd go for a designer look something swigly rather to say. That looks nice and unique.
You could try the bookshelves that resemble ladders depending on book size. They look as if they are leaning against your wall and have rungs like a ladder.