IMHO, I think hospitality related jobs are common around the Lakes. Restaurants, hotels, etc. Also, retail jobs had been good, where NH has no sales tax, but that is generally more concentrated by the major highways (I-93) and the borders. But, it's all a gamble in this market, really.
Having said that, three NH towns were just named
"most recession proof towns" by Forbes magazine (between 10,000 and 50,000 popoulation: Concord, Lebanon and Keene.