Helmet's save lives. Period. I don't think anyone familiar with the stats would even question this.
But here's another elephant in the room that few people are familiar with or want to talk about: how about the tens of thousands of dollars people and the state spend every year on people who otherwise would have gotten up and walked away from a motorcycle accident if they had been wearing a helmet? How about all the missed work days they could have avoided by wearing a helmet? How about all of the eye-injuries from rocks, bugs, sand, and debris from the road that is constantly flying in one's eyes? Ever get hit with a rock or insect at 50mph? It's enough to crack your visor.
And then there's the time spent in the hospital recovering, time spent in rehab, time spent at home in bed, etc.
I'm not for forcing people to wear a helmet, but myself, i always wear one, and cannot imagine not wearing one and having things bombard my face and eyes day and night. How about the rain? Ever get hit in the face by a raindrop at 65MPh? It's like getting shot!
Wearing a helmet is a personal choice, but i also think its a reflection of a person's intelligence.