All Plex channels are maintained and supported by a community of volunteers. If you want to find a list of channels that are most likely to work with your Plex app, work most consistently, and are regularly maintained, those would be the channels that are listed in Plex's Channel Directory. The Channel Directory is accessible from the Plex Web App by selecting Channels from the left sidebar and then the Install Channels button.
Channels available through the Channel Directory are considered stable, typically work on a majority of apps and do not contain content that may be considered offensive or questionable. But even these channels are still maintained by the community of Plex channel volunteers. Because these channel plugins are considered to be more stable, they are easier to maintain and update, so multiple channel developers may provide support, updates or fix issues.
Related Page: Channels > Adding, Removing, and Updating a Channel
Related Page: Channels > Channels from Other Sources