An MMORPG would be fantastic. Depending on how hard someone wanted to work, it could be developed from scratch. Or, Minecraft is, surprisingly, a good option for something like this. There are hundreds of plugins that include things that let you turn MC into an MMORPG with stats, levels, magic systems, custom mobs (monsters), weapons, items, etc. The problem is finding the right systems and spending months (if not years) building all the structures and areas, not to mention how blocky everything looks.
Still, either way is do-able, and could be really cool if someone was willing to put in the time and effort.
Chibi Chibi Rose said:
not really into MMO's
Maybe if they had an option for single player rpg then I'd be on it like Usagi on a donut
Sailor Moon: Another Story is a great one, if you can find a way to get it. Mind you, it's literally one of the hardest Turn-based RPGs I've ever played, but it's amazing.