IMH and simplistic O - there are 2 head shapes. I think your question needs to add the basic information - do you have a round head or an oval head? I have an oval head - bell helmets are torture devices. Giro are no better.
Lazer helmets rock.
I, too, am looking for a new helmet - one for an oval head, and with a flat back to it (a city style helmet). In the city style, all I can find are helmets for round heads.