Ampami RPG is an RPG server with a pretty complex story, and it is still being worked on. The server currently has 2 out of 4 chapters complete, so there is already a good amount to play through while more content is being added. The story takes place soon after the defeat of Krulp, the leader of a rebellious necromancer group, and the world is rebuilding after the damage that was left behind.
As things start going back to normal, a dire prophecy is made that another threat of similar scale is on the way... You will find custom mobs, custom items, and quests that can be either required or optional depending on how you want to play. There is also a pretty large map to explore, with even more coming in future chapters.
The story may be fairly linear, but the side quests and exploration give you plenty of room to wander off and do your own thing. If you want to follow the main path, you can do that too, so it works for players who like a guided RPG as well as people who just want to explore and take their time.