I'm surprised to hear about a helmet smashing into 1000 pieces, but helmets are designed to be "one time use". That is, after you've crashed with them, you should get a new one. They absorb energy from the crash by becoming deformed. Energy that goes into crushing the helmet doesn't go into crushing your head.

That said, I agree with the consensus. All helmets approved by a standard safety board (there will be a sticker inside the helmet) are probably equally safe. The key is to make sure you get one that fits. Many helmets have a universal fit gizmo, which is nice. The people at the LBS should be able to show you how to make sure you've got it properly adjusted.