I think that the elfa shelving system from The Container Store is genius. One top rail that mounts into the wall, and everything else suspends off said rail....what could be easier than that. It is perfect for people who hate to put holes in the wall, and people who hate measuring and leveling. I have two large elfa shelving systems in my house, and they hold an unreal amount of weight. Maybe it's magic.
The only thing I don't like about elfa is the actual shelves that the Container Store sells for the system. They are short, so you have to string a bunch together to get long horizontal shelves, and they are way too expensive (in my opinion) for veneered pieces of pressed particle board..(i.e. fake wood)
I have found a solution to this elfa shelf dilemma that is much more economical than purchasing the pre-fab shelves. I simply buy wood from the local home improvement store and make my own shelves. The only difference in using the elfa shelves and using wood is that you will have to buy some small wood screws and screw the brackets into the wood once the shelves are in place instead of using the pins that come with the pre-fab shelves and brackets.
elfa brackets come in several sizes, so once you decide on how deep you want your shelves and what bracket to purchase, you can buy planks of wood in the chosen depth. The great thing about stores like Home Depot is that most will even cut your wood to size for you for free.
Since the shelves are made of wood, they can be painted or stained to coordinate with their new home. There are so many options for what your shelves can look like. I have painted my shelves to match the color of my wall, as shown above and below.