1. Clique/Vuhdo style addon that allows you to bind your healing spells to your mouse and allows you to switch between them by holding down shift/ctrl etc
2. Bag addon that melts your bags together into one
3. MyRoleplay addon that allows you to set an RP tag (Ic, Ooc, Heavy/medium/light rp'er type) so that others may see it, allows you to add a brief physical description of your character and change its name so that when people with the addon mouses over you, they can see the new name (with the normal screen name written below or so) and to add some general notes.
4. A Gryphonhearts Items style addon that allows you to create linkable and tradeable "items" though without them being physically present in the game. They won't benefit you in any way, its simply a way to make more RP props.
That's all I ca think of for now.