Suggest best Portrait lens for Nikon D3000 camera?

I have bought Nikon D3000 and still have some spare money to buy any additional lens. Please suggest what is the best lens to take Portrait shots. As I need to take photos of Female models which needs to become wallpapers later on for my website. I need a lens which can work in low light but have the ability to take crisp clear and quality portrait shots.

I have hands on DSLR cameras just need this help.

Best choice: Nikon AF-S 50mm f1.4G prime lens.

Second choice: Nikon AF-S 50mm f1.8G prime lens.

On a 35mm film camera or full-frame DSLR a focal length of between 85mm to 105mm is considered the ideal portrait focal length. Since your D3000 has a 1, 6x "cropped sensor" a 50mm lens on it will have the equivalent angle of view of a 75mm lens on a 35mm film camera or full-frame DSLR.

The quality of your results depends on your skill with the camera. When you say: "I need a lens which can work in low light but have the ability to take crisp clear and quality portrait shots." it makes me wonder if you have much experience with low light photography. Even with a fast f1.4 or f1.8 50mm prime lens there has to be sufficient light to allow you to use a shutter speed of 1/100 sec. Or faster to avoid/minimize blur caused by camera or subject movement. You may have to use a higher ISO such as 800 or 1600 and, unfortunately, your D3000 doesn't do well with higher ISO settings. It may be necessary to use a program like Noise Ninja to "clean up" any digital noise that results from a high ISO. Http://picturecode.com

85mm f1.4 af-s

But honestly, some studio lights and a 50mm f1.8 af-s will go a lot further.

Full body shots: AF-S 50mm f1.4G

Upper Body/headshot/larger studio: AF-S 85mm f1.4G (or 85mm f1.8G)

Http://shop.nikonusa.com/store/nikonusa/en_US/pd/ThemeID.18145600/productID.213468800

Looks like we're in agreement on this one with the other posters.

Now, the 50.1.4 is also a good choice if your budget does not allow for the 85mm.
http://shop.nikonusa.com/....213467400

If you bought your D3000 with a kit lens, that would be enough for portraits. If you insist on getting another lens, look at the 50mm f/1.8.

Nikon just released a new 85mm f/1.8 portrait lens.

While many people recommend a 50mm lens as a portrait lens because of the crop factor, if you want that all important bokeh, you need to go to a moderate telephoto.

And if you know how to "zoom with your feet", the telephoto focal length is not an issue. Some pros have even gone to using the Nikon 70-200mm f/2.8 for portraiture.

Any lens in the 85 to 110 mm range should work.

Publication of Photos of another person, be it a regular person or a model, and it the printed media or online, requires a written and signed 'model release' form; else you may find yourself in court.