Helmets are pretty much all tested to the same minimum level of protection, so if there are any that offers MORE than that, no one knows about it.
The best helmet is the one that gets used.
So worry about that hurdle rather than about brand or model.
First thing you should do is lead by example - wear a helmet yourself.
Next, talk to your kids. Find out what they like and dislike.
Maybe they like skateboard helmets better.
They offer a comparable amount of protection.