Kaleidoscope museum in Manchester, Nuthin but Good Times in Merrimack, Bobo's indoor playground in Nashua, SEE Science center in Manchester, Nini Bambini in Bedford, My Gym in Bedford, BounceU in Bedford, Fishways in Manchester, Charmingfare Farm in Candia, Canobie in Salem...
Re: Places to take kids
Not in NH but right over the border....there is a place called Imajine That . My nieces and nephews love it
http://www.imajinethat.com/index.html
Also try Children's Museum of NH
http://www.childrens-museum.org/cmnh2010/default.aspx
The Discovery Stop in Londonderry
http://www.thediscoverystop.com/
A great blog with tons of places in NH
http://www.onemomsreview.net/2002/02/new-hampshire-attractions.html
HTH