I'm using this, except all-gray:

http://www.officedepot.com/a/products/234750/WorkPro-PRO-Quantum-9000-Series-Ergonomic/

I absolutely love it. The best investment a programmer can make is a good chair.

I cant access that site

This one then.

In general, you should always look for a chair with either a good mesh back or fully cushioned leather (a la "executive" chairs). Which depends on whether you want a full-back or mid-back. I prefer the latter. I also prefer to have a mesh seat over those dinky cushion things.

Mesh chairs are ideal but can be pricey, especially for something like an aeron. However, if its at all reasonable that you can afford it, a nice chair really is a solid investment. Not only will it last you many, many years, but you spend a lot of time there -- enough time for the quality of the chair to have an impact on your health. On top of that, you'll find that a good-quality, comfortable chair that fits you will help your productivity. Its not a place to skimp if you can help it -- much like the mattress you sleep on at night.

Right now I've actually got a fairly expensive, all-steel chair from Ikea that I've found isn't really comfortable for long stretches. I got it because I like to recline and I repeatedly broke typical $100-$150 office chairs every 12-18 months. I've got my sights set on an Aeron now, and I have every intention that it'll be the last office chair I buy. I know people who've had their Aerons going on 15 years -- you can actually have them refinished by the company (you just mail the mesh/upholstered parts, which isn't free but a whole lot cheaper than a new Aeron) because the mesh can eventually wear out. It's a lifetime investment.

I shelled out for the Aeron, but I'm not a huge advocate of it. I've seen that IKEA chair mentioned a lot but never liked it. My favorite chair is a random HON office chair that was being thrown out at the University, and held up beautifully for another eight years. I've tried a couple other HONs and liked them.

Passing on a tip I was given: look for office furniture surplus stores. Oftentimes hotels, offices, etc will go out of business or remodel, and these places will get perfectly good furniture to resell. That's how I got my Aeron at a stomachable price.

For the price, Ikea's MARKUS chair is damn hard to beat.

It's no Aeron, but it's comfortable for extended periods, and it also won't set you back a grand.

I took a look and must say it is the one of the evil chairs. A good chair that will not take away your lower back should have the bottom outcoming, not incoming. It should be rather like a small "knoll", instead of a small "chasm".

And I personally love and use chairs without hand resters, like this

But of course this chair given up is "chasm"-like, the knoll-like chairs are rather rare to my surprise.

But general advice would be, if you notice pain in your lower back (big one), change the chair immediately, whatever it is.

I always sit cross-legged. So I need a chair with a wide bottom, and armrests that won't get in the way of my knees when I cross my legs.

For the price, Ikea's MARKUS chair is damn hard to beat.

It's no Aeron, but it's comfortable for extended periods, and it also won't set you back a grand.

I'm also very happy with my (even cheaper) VILGOT I hate arm rests with a passion, and I really like mesh-back chairs (less sweaty in the summer)

A few years ago I got an offer to buy one of these through my work (though mine is black): http://www10.kinnarps.com/Images/Products/DeskChairs/Highres/9334N35.jpg?width=800

Lovely chair.

I've got the same one at my current employer.

Though the first thing I did was to remove the armrests, they do nothing but create neck and shoulder pains. (That's a general statement for armrests, not just for this chair...)

I have so many sitting hours in it it's ridiculous. So even if it's fairly expensive, I'm sure the cost per hour used is much less then most cheap chairs that break. (not to mention all the avoided pains)

And I personally love and use chairs without hand resters

I hate arm rests with a passion

As with most things IKEA, the chair is modular, and the armrests unbolt without affecting the structure of the chair (I initially didn't attach the arm rests, but they are nice).

You can also tthis aising your keyboard to elbow height and not sitting at all ;)

I've heard there are some quite good health benefits to this, but I am not quite sold on the idea...yet.