Chairs that Won't Wreck Your Back?

texatut asks: "I'm sure many of you are familiar with this secenario. You spend 10-12 hours a day in a crappy chair, and your back pays the price. I know there are chairs there that cost in excess of $1000 that alleviate the problem, but that's a lot of money to pay for a chair. I wanted to ask you all to give recommendations and opinions on chairs that are in a slightly lower price range, say, below $600. My back thanks you in advance."