Well it's not Charlestown! that it the good point

If you like a quiet area then Pepperell, Groton or Townsend are terrific places to live especially for children (Lots of running room and forest) Now that Taxachusetts has uped it's taxes Pepperell would be the best choice with the NH State bordering it (Shopping yeha) All towns listed are 10 to 15 miles from any highway. you also might want to look at Westford which is pretty nice also. I belive, but without any knowledge that all the schools are very good!
Good luck in your search.