Flag of Maine
Too many US states have a state seal or something similar centered on a blue flag. Maine's typifies this, with just a tiny coat of arms in the center. I'd base the flag off the shield in the coat of arms, a tricolor of blue, green, and blue, for the sky, forest, and water. I'd keep the tree and moose, because moose are cool. I'd also add the star emblem from atop the coat of arms, because that's a nice state symbol. No words, though. Mainers will have to remember "Dirigo" without it on their flag.