It's kind of hard to find information about relays that are out there, since it's not a feature often talked about.
But the one I am planning to use is https://federation.stream. They seem reputable, and also make an effort to block shitty instances.
Right now they're down, because like many high-traffic fediverse services they're seeing a lot more activity than usual this week, but I'll be enabling the relay when I can.
labyrinth.social is a small, invite-only Mastodon/Hometown server for pals who are in a labyrinth.