17. Water, water and more water. If you like being next to lots of water but still want the benefits of living near a population center, then this is your only choice. Bays, bays and more bays plus the ocean to boot. I've traveled most of the state (save North of Lancaster) and IMHO, if you are a "wateraholic" nothing comes to close Portsmouth in this area. 18 miles of coastline, not to mention what's available in Maine as well.
18. NH has no Sales Tax thus everyone on the Maine border shops in Portsmouth, which means the shopping options compare to a a city of 100K+.
19. Population, 21,000+. Enjoy a small town feel while having the ammenties of a much larger city.
20. Prevention Magazine named Portsmouth one of the top 100 walking cities in the America for 2008.