At our office we have Haworth Planes Height Adjustable [1], which I like and many others that visit inquire about them. They are premium but they will last, cost is ~$1,200 [2]

Pro-tip, get the wheels; everything should be on wheels, makes all the difference.

[1] http://www.haworth.com/home/resources/design-tools/image-sea... [2] a reseller has one on amazon http://www.amazon.com/Haworth-Planes-Height-Adjustable-Desk/...