Here I'll be posting plugins which ( I think ) would do a great job on the server.

Usable Books:
This plugin is called BookWorm, and allows you to read/write books, as well as putting them on bookshelves.
http://forums.bukkit.org/threads/fun-mech-bookworm-v1-6-read-and-write-books-1000.22159/
I think it would be great for RPG purposes.


Praecantatio:
Magical Plugin, w00t!
http://forums.bukkit.org/threads/fun-rpg-praecantatio-v1-2-a-magic-plugin-based-on-incantatio-now-with-permissions-1000.24959/
If Joe considered adding this plugin, i would advise to carefully choose permissions, or else people might get crazy with spells.

MultiCurrency!:
This could be great for RP purposes (Though it might create problems)! Imagine if every nation/town had it's own currency.
http://forums.bukkit.org/threads/econ-rpg-multicurrency-v0-09-the-only-multiple-currency-plugin-1000.26455/

God POWERS:
It's something for admins to be more effective and epic at the same time.
http://forums.bukkit.org/threads/admn-misc-god-powers-harness-the-power-of-the-minecraft-gods-1000.1097/