Brunette for the winter, blonde for the summer! Or, as Shellygrrl suggested, a happy medium- brunette with subtle, golden highlights (not a fan of the ombre myself). Of course sticking with your natural hair color will save you from some damage (I'm a natural brunette who bleached blonde for years. Going back to my "roots" was one of the best things I've done. Though I don't think I looked bad blonde, my hair looks & feels so much healthier now!)