The ThinkPad X1 Tablet is the most versatile Windows 2-in-1 yet, thanks to a unique modular design that lets you attach not only the included keyboard but also projector and 3D camera modules. The 12-inch business-friendly slate also boasts a vivid 2160 x 1440 display, a durable chassis and comfortable active pen. The ThinkPad X1 Tablet ($1,029 to start, $1649 as tested) is a strong performer and extremely portable, but you’ll need to spring for the high-capacity battery if you want long endurance.