Difference between the NIKKOR 18-200mm, 18-300mm, and the 70-200mm?

I need a lens that has a good quality zoom (all the way) without narrowing down the range to much. It'll have to be good for nature as well as, portraits.

I do mostly nature photography at different times of the day so lighting can't be an issue. My portraits are rarely done in doors and are never in a studio.

My photographs can be viewed on FB.com/TheBeautyThruaLens.

Which lens should I buy? Price aside.

Well, having looked at those photos, I have to be brutally honest and say that if those are representative of the best you can do, the 70-200 would be wasted on you. It is a seriously high level piece of glass, and expensive to match. The quality is superb, but you wouldn't be able to get the best out of it.

The 18-200 and 18-300 are all purpose lenses which will do many things acceptably, but none superbly. They will have considerable distortion at the wide and tele ends, but this is generally easy to correct if you have a recent enough version of camera RAW (or any software which allows lens profiles).

On their own they are competent lenses, but compared to the 70-200 their weaknesses are not hard to see. It's very much a case of you get what you pay for.

I would counsel you against the 70-200 until your photography has significantly improved; then as for the remaining two, the difference is mainly one of zoom range. The more zoom range, the more compromises you have to make. If you're shooting on a DX body, then the 18-200 should cover almost any situation you find yourself in.

Consider the following:

The more mm, the closer a distant subject will appear to you. The 18-300mm wins here.

The shorter the zoom range, the better the optical quality of the lens. The 70-200mm wins here.

To get the best of both worlds, get a 70-300mm for nature shots and use your 18-55mm for everything else.