The super-compact, tube-shaped ROAM2's simplicity has made it one of the most popular action cameras on the market. It takes full HD video up to 1080p and 5 megabyte still photos. It's fully waterproof without a case, so it can be used to take underwater footage, and features laser alignment. The two included mounts (one Profile, one Rotating) attach easily to helmets, bikes, or skateboards.
Like the Contour ROAM2, the Bullet is small and streamlined, with HD capabilities and a 9 megapixel still camera. It's waterproof up to 10 metres, has a fisheye lens feature, and comes with four mounts, including a Pad Mount, Universal Mount, and a Roll Bar Mount.
Although Sony's Action Cam looks like a regular camcorder, it's still compact and streamlined, and includes Wi-Fi, Smartphone Pairing, and a 13.5 megapixel still camera. It also has an optional wireless remote, so a second person can view the action on their wrist. While the Sony Action Cam is not waterproof, it comes with a clear waterproof case that keeps it functioning at up to 5 m.
While the Ghost can be mounted to a helmet, its larger size and remote system make it a good choice for mounting on objects - you can even synchronize up to 4 Ghosts for simultaneous use. With built-in Wi-Fi, the Ghost has a continuous looping feature, making it great for live streaming and as a dash cam. It's waterproof up to 3 metres without a case, but add the waterproof case, and you're good to go at up to 60 metres.
With a rectangular shape and a look reminiscent of a point-and-shoot digital camera, the Hero 3 doesn't look like much, but it is consistently rated as one of the top-of-the-line in action cameras. It's tiny, highly versatile in terms of mountings and wearing options, and delivers top-notch video and audio. It's Wi-Fi compatible has an optional Wi-Fi remote, an app that allows you to access controls from your phone, and a waterproof casing that keeps the Hero 3 functional at up to 60 metres.