Herman Miller Aeron Chair

Designed in 1994 by Don Chadwick and Bill Stumpf, the Aeron is the most studied, most imitated, and most resold office chair in history. The mesh back provides ventilation that foam chairs can't match. PostureFit SL supports the sacrum and lumbar independently. The tilt mechanism lets you recline while keeping your feet flat. Three sizes (A, B, C) mean it actually fits different body types instead of claiming "one size fits all." New Aerons cost $1,395-1,895, but the robust used market means you can get a refurbished one for $600-800 that will outlast any new $300 chair. The 12-year warranty covers everything. It's not the most comfortable chair for the first hour — it's the most comfortable chair for year five.