The best replacement for leap motion is kinect.

The best alternatives to leap motion are rated as following:
★★★★★  kinect
★★★★  myo
★★★  kinect 2
★★  duo
★  touchsmart
★  touchscreen
★  primesense

Your alternative for leap motion is not listed? Suggest!
Speaking about leap motion, one probably shouldn't forget about oculus rift.

Other search terms related to leap motion and their ratings are:
★★★★★ oculus rift
You have in mind a companion for leap motion and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of leap motion in all years. Click on graph for more.
leap motion
kinect
myo