I just bought a Nikon D 80 and Sigma 18-200 mm 1:3.5-6.3 DC Lens. It is my first SLR Camera and I was wondering if anyone had any other Lens that I should purchase? I am going to be taking pictures of Landscapes, Buildings and Sporting events. Are there any accessories I should get. I did purchase a Haze reducing lens cap as well. Thank you for all of the help.