Last year, we praised Apple for integrating tablet aesthetics into OS X Lion, thus starting the inevitable merger of tablet and computer. This year, Microsoft took the idea all the way with Windows 8. In addition to being Microsoft’s fastest operating system to date, Windows 8 runs both the new tiled Metro interface for touchscreens and tablets and the familiar desktop for traditional PCs. And because Metro apps go to sleep when not in use, machines could also get bumps in battery life. From $40