The GoPro Hero, was their "first" generation Hero. IMO, it lacks the quality of the newer Hero's. I own both a Hero and Hero 3 Black Edition, and the quality that the Hero 3 produces is light years ahead of the original Hero. I have never owned a Hero 2, but I would say go for the Hero 3 Black Edition if you are serious about image quality and features such as 2K shooting. If you just want to mess around with it, go with the Hero 2 or Hero or Hero 3 White or Silver editions.
The contour is another option, you can find the newer version fairly cheap online. Then again the color quality of the gopro is a bit nicer, in my view, when the clips are raw. Get what you can afford.
The new Black Edition is fucking incredible. The wi-fi feature is super useful, and the footage is awesome. I haven't used anything other than the free GoPro editing software and I'm still impressed with the quality. With a real editing program I'm sure it would be even better. My only gripe with it is battery life, but the spare batteries are pretty cheap so I just carry an extra.