Just picked up an HJC FS10 after using an AC10 for ages. Loads better fit, lighter, really good value for the money (£200). I've had an Arai before that was £400, and I don't rate that a lot higher (HJC 8/10, Arai, 8.5/10 max).
Plus, it has a cool integral sun visor that is easy to use, and...