I need the best, ergonomic Programmer's chair!

Hello, All.

Can anyone suggest to me the ultimate chair for programmers? I am spending more and more hours in front of my pc programming, and my lower and upper back, as well as my elbows are killing me! I have gone through 2 chairs already that were supposed to be ergonomic, but they dont really work like I need them to.

Is there a chair of choice for programmers?!?!?

Help!!!

-kaanuki-