Best portrait lens for nikon d3000?

I want to take super crystal clear portrait pictures with my d3000.
what is the best lens for this?
also, is this a good lens? Http://www.henrys.ca/61708-NIKON-AF-S-DX-55-300MM-VRII-4-5-5-6G-ED.aspx

Actually, in my experience, any good lens will do it if you know how to operate your camera.

I'm a Canon guy and here's a couple done with my 28-200 lens.

To my way of thinking the 55 you mention is too tight. Every time you want to shoot a portrait you'll have to back up and your shot is already magnified to 55mm.

Before even seriously considering this lens for what you're talking about, if you have a kit lens,
zoom it to 55mm and see how far you have to back away to get say a head and shoulders shot.

Also consider the f/stop at 55mm, how much light will you always have to add, that kind of thing.

You want a cheap bright prime lens with a flattering perspective and shallow depth of field.

You want a Nikon AF-D 50mm f1.8.

It will behave more like a portrait friendly 75mm on your D3000 thanks to the cropped sensor, has massive depth of field control, and will be much more accurate to focus manually (you will probably only be able to focus manually as there's no AF motor in the D3000 body, which the AF-D lenses require) but for portraiture manual focus really is better.

The lens is amongst nikons cheapest too, and will, when used correctly, give very professional looking results that exceed the money spent.

Superzooms are full of distortions, dark and limited depth of field control by comparison.

A nifty fifty never made more sense than on an APS-C type body for portraiture.