Sorry dazzleman... but I vote for Connecticut.
You have a point. But the great thing about our state is that while nothing is here, there's tons to do right over the borders in New York and Mass. Thats why we have so many suburbs, people live there but work and have fun in other places.
I'll say North Dakota
I read somewhere that if its population trends continue, the Census Bureau will start to reclassify large parts of it as "frontier". I don't know what practical effects that would have. Maybe the government would start giving away free land like in the Homestead Act
ND, rural Nebraska, Kansas and Oklahoma also seem very boring. I've only been west of the Miss. River once so these are all assumptions.