Sigma 18-50mm f/2.8-4.5 DC OS HSM

good used one is great buy. Also this is Sigma 17-70mm f2.8-4 alternative Smooth Zoom and good build quality, good image quality for the price. OS is definitely plus to have steady shots. Also HSM enables to work with Nikon low end camera such as D40/D40x which do not have lens motor.

Great lens for the money if you have a camera that does not have auto focus Works really well but like many many others have noted, the F 2.8 only engages when your in the 18mm range if you go any further in it does not sit there. For what you pay for it the lens is worth it. I enjoy it but will prob be getting a Nikkor Lens down the road when I upgrade to a D7000. If you have a camera that already has Autofocus try a different lens.

very good inexpensive lens. Nice inexpensive lens. I like the fact that it doesn't extend as you zoom. The barrel length is fixed. The 2.8 very rapidly goes back up asyou zoom. So it isn't as useful as I had expected for fast lens work.