Shoei is the make for me, I've had AGV, Shark, Nolan in the past but have come back to Shoei. It depends on which one fits the shape of your bonce best first and foremost.
A few racers here in the UK are wearing (and testing) the HJC which always gives a lid some cred in my book.
Arai is top but does not suit my bonce as good as the Shoei.
You get what you pay for and if you've a £10 head you wear a £10 hat!!