For me it’s traefik. It’s took me a while to get it working, but it’s actually really easy now.
Setting up container access with labels is very convenient!
For me it's https://nginxproxymanager.com/ it's just so easy to setup and use. One docker command and you're up and running with a nice webinterface to manage access to your docker instances with ssl. I heard good things about Traefik too but I have no personal experience with that one. NPM does everything I need and if it ain't broken... :)