Bern does make really nice buckets, but if you want the one that'll save your head, buy a Sweet Protection lid. They've got the best shell construction of anything on the market. The way they build them allows any impact on a particualr spot top be spread out over the entire surface area so you don't get the "direct" impact feeling. Sweet is the shit. They're a bit pricier than most helmets out there, but it's your head, and that's an important thing to protect.
I've seen the Smith line for next (for whoever is was that was asking about them above), and they'll be good eventually, but I wouldn't recommend buying one this next year, they've got some kinks to work out, and it sucks being a guinea pig when you're talking about impact to your brain.