Game Hangout · Project Zomboid
The dedicated server on a friend's PC, Steam Workshop mods, one list for everyone. No rented box.
Free. No account. Server files: 6.7 GB, once, on the host's PC.

The server itself: the 6.7 GB download, once, on the host's PC; the tunnel to your friends instead of port forwarding; and the world that follows whoever starts it next. For your group it feels like a server that is always on, without anybody renting one. Steam Workshop mods, picked in the app, one list for everyone in the same order.