There are several solid action cams out there now. A quick search of YouTube shows countless reviews and comparisons. In my hobby of RC aircraft, the ~$80 Mobius cam is a very popular alternative to the GoPro. Most reviewers compare its video quality to that of the previous generation GoPro Hero 2, but it's smaller and much cheaper. Its firmware also supports it being used as a dashcam.

http://buymobius.com/collections/mobius-cameras/products/108...

http://www.amazon.com/Mobius-Action-Camera-1080P-Sports/dp/B...