I had a go pro 2 but I either I was doing something wrong or I had a lemon but I never got decent video from it.
I use a 60d. There is a Sony 4K camcorder for 2 grand I am looking to buy some time. 4K stock clips get a good price.
My GoPro Hero2 shoots very good video, of course not nearly as good as my Cannon HV40 (tape camera). The color saturation and picture quality looks like it was shot with a 3 chip pro camera.
Also consider the Panasonic GH-4, if you have Micro 4/3’s lenses.
If you have manual lenses most adapters are $20 on Ebay.