The problem is, I also want to be able to do MMORPG (Quests, dungeon parties, GM-Run events, etc.) stuff alongside sandbox stuff, not just full sandboxing. That's one thing I also try to find in most MMORPGs: Storylines.
I'm guessing I've only got FFXIV, even though it's too late to start hard mode content (Which is forced to do later in the story, a shame.)
Mortal online got a recent graphics and animations update. The fun starts when you get a good architect and a guild together. You can basically create guild towns as well as weapons to destroy said towns. If a guild is known for being a dick their is usually an alliance of guilds that goes out to completely obliterate them. It's pretty freaking intense if you get into that game. Just don't play alone! xD
ArcheAge, Mortal Online, Wurm Online, Minecraft, etc...
... That moment when you Google "labor camp".
You can construct bases and housing in Rust.