I am very happy with my new clear chair mat for my computer. With the grips on the back side of it holds it in place. I like that it is clear so it does not draw attention to it.
I have finally found a desk chair mat that will last more than a year or two. It does not "dimple" very easily from the wheels on the chair. The chair rolls easily on it.
I picked out the cheapest mat and it's not really suitable for carpet it's too flexible. It would work fine on a hard floor. Once this one wears out I will buy the more expensive one.