I use lined plastic sleeves from svp in the UK. The lining runs down the centre so you can put two discs in one sleeve. You get 100 sleeves for about Â£2. To store them I use empty Duracell battery boxes I get for nothing from a local shop (they throw them out anyway) The 4 battery compartments are the perfect size for DVD sleeves. DVD cases of any description take up too much space, and storing them in spindles is a pain when you need to get the disc at the bottom! I always keep the disc boxes in a cupboard away from light.
Makes me laugh how we ever put up with VHS tapes!