Your Local Book Store
The best spot for book is your local used bookstore. I love walking into mine and just browsing. Prices will be comparable to online, if not cheaper due to no shipping cost. Not to mention, you can trade used, unwanted items in for store credit. I also just like to hold the book, read the back and flip through it more than I like reading about it on the internet.
In a close second is your local library. You can own any book there for free… for a couple weeks at least. I love going to the library and impulsively checking out some interesting looking stuff. Amassing a stack of books also motivates me to read more. Personally, I feel the an urgency to read when I have a bunch of book lined up, rather than one. The reasoning is that if I only have one book then I can take my time with it, and missing a day of reading wouldn’t really set me back at all.
Amazon is going to take over the world. Is there anything they don’t sell? No. I don’t think so. Any book you could ever want is for sale on amazon, and probably been rated and reviewed by a couple other people. When you search for a book, Amazon feeds you similar books with their magical “customers who viewed this also viewed…” feature. Amazon is a great overall book resource. You can read reviews, see ratings, learn the summary, or discover new books in a flash.
The Book Despository is up there with amazon. Huge stock of new items, with free shipping on everything. Prices tend to be a litte more expensive than Amazon, but you are getting free shipping. Amazon usually makes you pay $25 to get the free shipping (unless you have Amazon Prime), so if you are set on only buying one $15 item, TBD may be the better alternative with their free shipping.