Bern has the right stuff, and the foam that actually works. However, as with any helmet try it on before you buy, because a helmet that doesn't fit does you no good whatsoever.
my head fits like inbetween a large and a medium in my red helmet, if i got a bern helmet what size do you think would fit best? and is there any reason to wear a hat underneath? or do the liner things do the same thing?