Here is a bit of a Pinterest splurge. I love that site and I've been browsing for ages about bookshelf ideas as mine are getting really cluttered. 

I love this bookshelf as its so different and it would really be a feature piece on a wall. Only if you had a massive home though! Regardless it would look like the trees were full of flowers with the spine of each book. 

Love the under the stairs idea, mainly because it would work really well if you don't have much space and you could easily use it to store other things (though books are always preferred!) It looks beautiful and would look even better with the books all colour co-ordinated. 

I absolutely love this coloured bookshelf idea as it really makes them stand out. And I love the blue colour! I would love to do something like this in max's room either by backing a bookcase with some colour or paint or to paint the whole thing so that it stands out more.