The best office chair is not the cheapest one nor the most expensive one, it should the chair fit you best, on your budget, comfortable during your sitting hours, and fit most of your special needs. We will be glad if you can find a right chair here!
Most good office chairs are highly adjustable, allowing you to customize your posture to meet your needs. Height, tilt, and the angle between the seat and the back are all adjustable on most decent chairs. More advanced models may give you the opportunity to adjust the height of the armrests (very important for comfortable typing), the lower back support, the position of the headrest, and even the firmness of the seat and back.