Iceland
Iceland is a land of gorgeous natural beauty: glaciers, volcanoes, waterfalls, geysers, wildlife and hot springs. It is also an adventure sport destination: ATV's, helicopters, snow mobiles, horseback riding and 4-wheel driving.
It is a destination that is great for all kinds of travelers: families (with children over 8), couples and groups of friends traveling together.
Summer and winter are both good times to visit. In summer the highlights are waterfalls, hiking and ATV's. In winter the highlights are the Northern Lights, glaciers and snowmobiling. Bathing in the hot springs is a year-round activity. The weather is unpredictable and more temperate than I thought it would be (summer is cooler than I expected and winter is warmer). The summer average is mid-50's/low 60's and the winter average is around freezing.
Reykjavik is a 5.5 hour flight from NYC and a 5-hour time change. There are several daily non-stop flights from New York.
A long weekend is enough to see Reykjavik and do a few day trips from there, but a 6 or 7-day trip is needed to get out into the countryside and experience all the country has to offer.