We have installed most of the windows and doors for the house. I usually specify a window that is aluminum clad outside and pine wood inside. I like the aluminum clad because in my opinion it is one of the most weather resistant materials to use. We have temperatures here that can swing from hot to cold (more cold then hot) and the aluminum clad hold up to temperature changes and retains the color well with very little fading. I also like to use a casement window vs. a double hung. There are occasions that a double hung is preferred, like space issues outside if a window opens up to a deck, but a casement window is more energy efficient than a double hung.