The new GPA helmet, linked to above on the Smartpak site, looks interesting, but WOW! at a price that I’m betting few will plunk down. (List price of $800, discounted to 748).
I’ve been using a UVEX perfexxion. I like it because it’s light, well-ventilated, and it fits my head well. I’ve owned Chas. Owens in the past, but found them oppressively hot in the summer. I liked the UVEX partly because they produce helmets for all kinds of sports as well as for the military–it seems like they’ve done the research.
Overall, I agree that it’s important to get a helmet that fits correctly. Not only so that you’ll wear it, but also because a helmet that fits is a helmet that won’t shift or gap, and thus is more likely to provide consistent protection when/if you fall.