The Sim Chair designed by Jasper Morrison and made by Vitra looks like your basic sled base plastic chair, and while its priced like one there are intelligent design decisions that make it a superior chair.
First the roll front of the plastic seat makes the chair much more comfortable than your average plastic chair. Never will you have the knife edge of the plastic seat digging into the back of your knee. Also the flexible back piece gives the chair some resilience and flex that you often don't see in a chair like this. The flex is reminiscent of a task chair back and makes longer sitting periods more comfortable.
It also stacks for storage - always a great help when you work in a small space and don't need all the chairs out all the time. I have four of these for our meeting area, so I'm bias. We ordered them with contrasting color for backs and seats - an option you won't be offered on most chairs in this range.