I would have to suggest "titan panel" and "lightheaded" or "questhelper".
Its really hard to say whats the best, but in my opinion all you need is a panel of information and quest helper.

In my opinion, I feel that the best addon is MobMap. MobMap provides the location of any NPC or MOB in WoW. It also can find the location of any item that can be picked up off the ground, such as; Herbs, Veins, and any quest item. Another useful thing is its ability to find a drop item, tell you what it drops from, its drop rate, and where to find the monster. It is extremely useful!

Deveant