The style of MC that I love is the whole Towny/loose RPing thing that you see a lot of in multiplayer. We'd build towns, form nations, have little battles, etc. There was local government and little goofy things that weren't taken very seriously, but still a lot of fun. The server had a lot of issues though. Such as the owner being the final word on everything, but not playing the game at all other than to check in occasionally. I set out to create my own server with a similar premise, but sans the issues...but man that is a lot of work to do alone!