http://www.nikonchat.com/18-200mm-nikon-vs-sigma/

Canon XSi T1i O – or lens kit update – That is the question
You are investigating as if ever, talk back and forth between the two cameras, since it can not decide if you need the video of the T1i or just want to take great still photos that the XSi will give more than $ 100 less.
You decide on the T1i … Ugh! Then you find the whole debate about the purpose of the kit on the forums of the camera.
"Wait, are you saying I need to consider purchasing another purpose, besides the kit lens? "I asked." Is there another way? "
Consider this. Get a lens instead of 2 or 3, but that's a good idea. In this way, you can keep the same camera lens for wide angle landscapes or family photos, and only zoom to telephoto to take that picture of action in the football game.
Canon (and Nikon) play the same game. They put a pretty good lens of their cameras by Rebelde as a kit lens. You get the camera and realizes he wants more … either quality or zoom capability. So you're stuck in the position of that many owners of a new digital SLR to include … Additional lens should I buy?
I have a suggestion for you. One word – Sigma 18-250mm F3.5-6.3 DC OS HSM Lens – Well, I lied, not a word. But it is a powerful suggestion. The image quality is impressive, it's great for wide angle optical zoom and stabilization you have (the same as anti-vibration), and will make you happy!
Newcastle, he said.
Actually I have nothing else. If you are interested in this idea, There is more information for your reading enjoyment in http://www.squidoo.com/Sigma 18-250. Also head http://www.digital-photographic-resources.com to learn more about this impressive lens and a few others, too. Happy Shooting!
About the Author
I love photography and all things related to it. Cameras, camera gear, and image editing software fascinate me, so I am either buying the newest piece of equipment (or software) or researching my next purchase.
Sigma 18-200mm F3.5-6.3 DC OS HSM for Nikon D60 – Part 2