NH is kind to political outsiders. Buchanan won it in '96 and I think Sanders has a very good shot of winning it in '16.
It seems like recently, NH has been better for the 'establishment candidate. In 2000, Gore won it. In 2004, Kerry won it. In 2008, McCain and Clinton won it. In 2012, Romney won it.
Iowa seems to be more likely to favor insurgent candidates, at least recently.
To be honest, I feel that Bernie Sanders is a much better fit for New Hampshire than Iowa. I don't think that he will win the primary in either state when all is said and done though.