Nikon 18-200mm or 28-300mm?

I have a nikon D5100.
if i want to buy a tele+wide lens, which one is better?
nikon 18-200mm, nikon 28-300mm, or Tamron 18-270mm
which one have the best build quality? How about the image quality?
price list?

I'd go with the 18-200mm. Leave Tamron at such long zooms, these lenses are generally bad.

Here's a Lens Buying Guide - http://www.the-dslr-photographer.com/2009/11/buying-a-lens/