The best replacement for gopro is contour.

The best alternatives to gopro are rated as following:
★★★★★  contour
★★★★★  sony
★★★★  camcorder
★★★  dslr
★★★  drift
★★  ion
★★  sony action
★★  virb
★★  garmin
★  waterproof camera
★  sony action cam
★  flip
★  action cam
★  point and shoot
★  gear pro
★  mobius
★  jvc
★  contour gps
★  vholdr
★  playsport
★  vio
★  underwater camera
  olympus tough
  adixxion
  gopro2
  kodak
  pov
  flip video
  garmin virb
  vivitar
  drift hd
  atc9k
  contourhd
  flip camera
  ion air pro
  looxcie
  kodak playsport
  xd
  nikon aw110
  sealife

Your alternative for gopro is not listed? Suggest!
Speaking about gopro, one probably shouldn't forget about fisheye.

Other search terms related to gopro and their ratings are:
★★★★★ fisheye
★★★★ zoom
★★★ imovie
★★ drone
★★ external mic
diving
helicopter
You have in mind a companion for gopro and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of gopro in all years. Click on graph for more.
gopro
contour
sony