I've recently had a Titan shed put up in my backyard. It's 20' long and 18' wide and 8' high. It's strong enough to hang an engine hoist off the beams and has 4 double fluoro lights and a double powerpoint in every corner and two power points suspended from the ceiling. All my spares are on shelves down one side and a work bench and all my tools are on the other side and even with the doors open, I can quite easily walk around the car. It has a 10' wide roller door in the front and an 8' wide roller door at the back. I can quite easily drive straight through the shed with the car on the trailer and I can also park the trailer in the shed with the car on it.
As you can tell, I love my shed.
I've waited nine years and in that time I've put a lot of thought into just what I need.