I know me and my Wife used to share her cutting mat.
Recently Wave in Japan released this:
http://www.hlj.com/scripts/hljpage.cgi?WAVHT-091
Good points:
1) mm & cm markings (no imperial markings though)
2) circle diameters (5mm ~ 50mm in 5mm increments)
3) Ankle indicators from 0~180 with 30, 45, 60, 90, 120 135, 150 premarked.
4) Grid markers for 1, 2, 3, 5 mm grids
Nothing really special I have seen tons of similar cutting mats in the arts supply section, sizes up to A1.