I get a new helmet every other season or so. They say once it takes a good beating you should replace it because it might have structural damage. Mine takes a pretty good beating every season, so I just get cheap ones and replace as needed. Current one is a giro something-or-other with a flame job h: I need a new one asap

:edit: I got a concussion right through my old helmet and it was also a good name brand. Now I don't worry too much about the brand.