Keep it on topic or don't post at all guys. Mccall, i'd much prefer a wooden self-assembled affair every time. Not only you get the satisfaction and experience and growth of putting it together myself. But you can paint it whatever (manly) colour you choose to boot. I like the idea of having a permanent refuge that I can fill with old half empty tins of paint and glass jars of assorted screws and nails.
Man-space.
I may well post a link to my ideal shed, but as this is such an important decision, I can't take it lightly and need to research the mainstream sites like b&q and homebase etc.