I really enjoy my Garmin Virb Elite. A smartphone with the app can be used as a viewfinder, though I'd be surprised if most cameras don't have that functionality at this point. It's got similar ergonomics to the Contour and Sony -- i.e., more of a tube than a box. And it's water resistant right out of the box, with a dive case available if you want to use it for any sort of deep-water swimming/diving. It comes with a "third-party mount adapter," AKA an adapter to mount the Virb cradle to GoPro mounts (many more options than Garmin) and standard camera tripods.
But the main criteria that tipped me towards the Garmin rather than a GoPro is all the data that's available directly from the camera, because I'm a geek like that. The Virb editing software makes it super easy to overlay that data on your videos too, so you can see how fast you're going and how many Gs you're pulling in those hard turns.
Garmin has released some new Virbs recently, though I'm not familiar with those at all. I assume they'd offer the same functionality as the earlier cameras, just with different technical specs.