I have done alot of research on Gazebo's after 2 have broke on me this year, both were inexpensive ones that seemed ok, but after using them awhile the steel frame broke.
So I am going to buy an Ez-up brand gazebo. These are much better quality, yes they cost more, but as nigs said they last years, but they are out of stock at the moment, they are waiting their container from the states, should be here very soon though, I am getting the Dome II with sides and a stake kit, it's gonna be over £200, but if it lasts for years then it's worth it!!! Here is a link
http://www.ez-up.co.uk/index.htm