Indeed https://github.com/potree/potree has a bit awkward navigation, but there are quite a few nice lidar datasets available to explore with it, like the scan of the Matterhorn. I once used it to explore a dataset made by a photogrammetry drone, was quite nice.

The entire country of the Netherlands is also available here: http://ahn2.pointclouds.nl/ There is no rgb information, only elevation. But you can make out individual power powerlines, the scan resolution is really high.