A storage shed can be a very useful space when used appropriately. However, since it's a space that is used for utility, homeowners often don't give much thought as to how it is arranged. During the spring and summer months, yard tools are frequently hulled in and out to assist in landscaping projects. In the winter, you may have to scramble to find snow shovels and sleds, certainly not something anyone wants to do in a harsh winter.
For nearly maintenance-free storage units, vinyl is the preferred siding. Vinyl lacks the visual appeal of wood, but if you own a house with vinyl siding, why not select a storage unit that is also sided with vinyl? However, vinyl will get dirty over time, making it even less attractive. Mold is often the culprit. Take into account the maintenance required to clean the vinyl periodically.