18-200mm

The 18-200mm was the lens that I used 95% of the time on my D200, until I switch to the D800 earlier this year.  For travel, this lens is all you need; I went to China twice, and this was the only lens I carried, and never felt that I needed another lens.  And I was always happy with the IQ of the lens, I guess I am not much of a pixel peeper.