Nikon 70-200mm or sigma 70-200mm hsm?

I will be using these lenses on nikon d5000

Not being a Nikon fan, I can surely say that Nikon lenses are better than Sigma's.

If you can afford it go for the nikon.

I would agree, it's obvious, the Nikon. Never, ever base a camera gear purchase on price.

The Nikon 70-200mm is obviously better, but (not surprisingly) much more expensive.

If you're an amateur photographer, the Sigma 70-200 will probably give similar results for less. However, when you count in resale value, the Nikon can still end up cheaper because the Sigma lens will likely be worth much less a decade from now, while the Nikon's value will still be going strong.

As Nikon D5000 have DX Format so you must go with Sigma HSM F2.8 any zoom range. So you will be able to control morein low light situation.images will be sharper. Nikon lenses are good but they are expensive. Sigma lenses are not bad as peoples say it.