I like the Demon Flex Force Pro... or if you want to be Fancy the Demon Flex D3O Pro which hardens at the moment of impact.
The Flex Force Pro is exactly what I've got. At least the once pictured in this link...
Think I paid about $125 or so last year for it. Felt weird to ride in for the first day or so, now I wouldn't ride without it.
Even when I'm just groomer bombing it's nice to have an extra layer of protection.