Are there any really good rpg-style mmos that use unity web player?

You're asking about RPG MMOs built with Unity Web Player, which is a technology that is no longer supported. Unity Web Player was discontinued in 2017, meaning no new games can be created with it and most existing ones are no longer playable.

Therefore, there are no active RPG MMOs using Unity Web Player.

If you're looking for RPG MMOs, you can find a wide range of options built with modern technologies. Some popular examples include:

* World of Warcraft: A classic and highly-rated MMO with a rich world and a massive player base.

* Final Fantasy XIV Online: A beautifully crafted MMO with a compelling story and a deep combat system.

* Black Desert Online: A sandbox MMO known for its stunning graphics and challenging gameplay.

* Destiny 2: A sci-fi MMO with action-packed combat and a focus on cooperative play.

If you're interested in exploring MMOs built with Unity, you can find many options on platforms like Steam and the Unity Asset Store. Keep in mind that most modern MMOs are built with other technologies like Unreal Engine or custom engines for optimal performance.