It began with just the first four books... I received them at each at age 10, where I began reading them and growing up alongside Harry himself. From then onwards, I purchased the following books as they were released right up until I was 15. Amidst these teenage years however, I began to keep my love a secret. I was ridiculed in High School for rocking a Harry Potter pencil case and so I thought it best to blend in instead. As a result I never purchased or read Deathly Hallows until just this year!!!
In addition to the novels, I have been lucky enough to find some other Harry Potter inspired treasures hidden amongst the shelves of second hand book stores. The first supplement I came across was The Tales of Beedle the Bard. This is the wizarding world's equivalent of our Brothers Grimm, and appears in Deathly Hallows as a gift bequeathed to Hermoine from Dumbledore himself. I found my copy to be incomplete, and so I added the deathly hallows symbol at the top for authenticity.
I stumbled across the other two supplements while I was browsing another second hand store just the other day. The first, Fantastic Beasts and Where to Find Them, is a copy of a text book that belonged to Harry in the very first novel. The second, Quidditch Through the Ages, is another text book, this time belonging to Hogwarts Library.
I think the best part about owning this entire collection is knowing that the original purchaser's of the novelty companions have contributed to donating over $30 million to Comic Relief and The Children's Voice charity campaigns! Three cheers for Rowling's philanthropic work!
P.S. For those with brilliant eyes, no I am not missing The Chamber of Secrets. It was just on loan to someone when this photo was taken.