To get right to the point of my writing: I can't give you a definite answer. What I can definitely tell you right now is that we are to focus on the GoPro HERO4 and HERO3+'s (and I will touch base on a few HERO2 and original 3's as well), as it is the best technology and provides options for numerous consumers. With the recent announcement of the HERO4's especially, we'll tackle the main features of those to help you decide if that hefty price is worth it.
Although obvious, I put this here first because this is one of the most important factors when purchasing your camera. The HERO3 has three editions (white, silver and black), ranging from $199 - $399 (prices continue to drop annually as newer versions are released -- we'll keep you updated on those). The HERO2's are at the bottom of this gap, but aren't as "new" and lack some features the 3's have (they're discontinued at this point but can be found on the net here and there).
Don’t let its size fool you. The GoPro HERO5 Session may be small, but as a camera, it’s mighty. It focuses on portability without sacrificing power: it’s only an inch and a half tall, but it records in 4K and it’s completely waterproof. While it doesn’t have the touchscreen interface that other GoPro cameras do, it’s the only GoPro that can fit in your pocket.
The GoPro camera was originally designed by current CEO Nick Woodman as a compact means to capture photos and videos of him surfing. While the devices are often still used for this purpose, the company has come a long way in the 15 years since its initial inception, and GoPro cameras are now used by all manner of extreme athletes and adventurers, in addition to more casual users.
And sure, those options could include your waterproof and crack-resistant smartphone, but keep in mind that the best action camera is designed for this kind of shooting. Plus, just because your phone is tougher, it doesn't mean you should risk losing or damaging the thing that keeps you connected to work, family and friends. It's also way easier to mount one of these to your body, car, bike or anything else than your phone.