How much do you want to spend?
The 70-200mm F2.8 is an AMAZING lens...but its also $1,800.

The 18-200mm is the jack of all trades, but master of none...so its an alright lens...much cheaper than the 70-200, but a bit better than the $200 55-200mm F4.5-5.6

forget about money.

Get a VR lens that has the lowest aperture rating ... like f 2.8 or whatever the lowest is that Nikon offers for the longest reach. That's what a pro would use. So use that. Also check out using a teleconverter for this ... though i recommend nice light to use a telecon ... just because you will lose a stop.

highest glass quality

hmm nice i was looking at that lens too.. unfortunately since im a student i have a small budget for spending on glass
im looking at about a max budget of 700$... kinda narrows it down.. but later down when im done school i can focus on better more expensive glass.

dont get eny zoom with range like 18-200, so much zoom range means crap lens. Sigma 70-200 f/2.8 is desent and real cheap for a 2.8 tele zoom.