I got the Sony water/drop/cold proof 2+ yrs ago and love it. It's been abused by my two kids, pounded in salt water surf, etc etc. great pic and video quality.
Santa just brought me the contour roam- he knew I didn't want a go pro sticking up on my head like a p#!+er on a 14 yr old. First one had volume issues, second one rocks.
For a WAY cheaper option, as well as smaller, lighter, look at the tachyon helmet cam. Ordered the low end one (89 bucks!) for my 9 yr old for skiing and it's very impressive. Can clip on your hat brim it's so small and light. Worth a look.