Herman Miller Mirra 2

The Herman Miller Mirra 2 is a butterfly-backed desk chair that is not only comfortable but also provides loads of support; it even adapts to small movements, thanks to its fabric-and-polymer webbing. And it has a killer feature for those with back problems: Knobs on its spine let you dial in lower-back support. All testers said they could sit longer with less discomfort – half the battle at any job. [From $649; hermanmiller.com]