Nikon D90 review in detail?

And best lens for it? I've got the sigma 70-300mm but I want a wide angle lens.

For under $200, you can buy a Nikkor 18-55 mm lens that will give you what you want without making you go hungry for a few weeks.

Depending upon your budget, you could buy an ultra wide Nikkor 10-24 mm a 24-85 mm and those two lenses would round out your system. Just start saving your pennies until you can buy one or the other lenses. Like many photographers, you will eventually end up with at least 3 lenses, maybe up to 5 or more.

Time will tell.

D90 review here:
http://www.steves-digicams.com/camera-reviews/nikon/d90-slr/nikon-d90-slr-review.html

The problem with any D90 review is that it will have been written 2-3 years ago, so what you won't see if a fair comparison with newer cameras.

How wide do you consider to be wide?
For very wide angles I would look at the Sigma 10-20mm lens. It is reasonably priced for an ultra wide and good quality optically.

If you don't need to go that wide, the Nikon 18-105 is a very useful lens for day to day work, is sharp and 18mm is reasonably wide. The 18-105 is a much better and more useful lens than the 18-55 if you can afford it.

If you can afford more, the 16-85mm Nikon lens is even better.