CliveOverflow SMP is a long-running personal server with a ton of history behind it. The world is a big one, the save has grown huge over time, and there are goodies scattered all over the place, even if some of them are very, very far away. You can use /tpr for random teleporting, so getting out and exploring is part of the fun.
It's a semi-vanilla crossplay server for both Java and Bedrock, so friends on different editions can hop in together. Pretty much anything goes as long as you keep it fun, and there's /claim if you want to keep your chunks safe. If you want money for claims, /sell amethist is there too.
The world will never be reset, so whatever gets built or found here stays part of the server's story. If you like survival with a bit of freedom, some economy, and a world that already has a lot of weird old stuff tucked away, this is the kind of place to poke around in.