Replacing a window is a daunting DIY for most homeowners, but this double hung window from American Craftsman, designed to fit into your existing window frame, is a doable project. Dual-weatherstripping creates a tight seal on both sides of the glass, so you'll save on your energy bills all year long. And since vinyl doesn't need to be painted, you'll never have to touch up the frame. Sure, you'll still have to wipe down the window panes, but with a tilt-in top and bottom sash, cleaning is a breeze. Available at Home Depot; $167.00.