Let me take the chance here to throw out
Markshire: Kingdom of Ice as an appropriate RP focused world that's definitely worth checking out.
The world of Markshire incorporates the Norse mythos into a medieval DnD type setting. The world is 20 years in the making, having been the primary pen and paper world of the admins/creators. Overall, I think the world provides a great setting, yet also is flexible enough to incorporate many types of characters as the players see fit.
The world it low magic, slower levelling, and as I said RP focused (in character speech is exactly that, in character - though no one will run you off the server if you accidentally use the talk channel while bantering with your friends.
Really the best thing about Markshire is the community of people who play there. Everyone from the admins to the DMs to the players are awesome, and really most interested in creating a world in which to develop characters and storylines, while having fun. Markshire won a
Reviewer's Award from the Vault. Although the review is a bit old, many of the active players at that point remain, as does the DM/admin team. I'd say it will give you a pretty good feel for what the place is like.
More detailed info on the required haks, the server guidelines, the scripts in use, and the setting can be found either at the main
website (register in order to see all the forums). More information can also be found on the
Vault page.
So, hope to see you in the Kingdom of Ice! Bring your warmest cloak!