Atlas
Instance Maps w/ boss locations and loot tables
There is a plugin called
AtlasMajorCities that comes with loads of NPC's already marked on the map (trainers, vendors etc..).
Atlas is, IMO, the best instance map addon. You can use it with Metamap or Cartographer, no conclicts.
MetaMap
Feature rich map addon (see link for all features). It can record moused over npc's and allow searches for them later. Shows location icons on the world map and minimap. It does not come preloaded with any npc's but you can download and import
other users databases
I would suggest Metamap, tbh. It comes with just about every feature a map addon can have while still being fairly easy to use.
Cartographer
Similar to Metamap, this one will record npc's such as
vendors and
trainers (requires the respective plugins). It will create icons/notes on your worldmap.
I personaly prefer Cartographer w/ plugins. Its Ace2 and the plugins rock. Plus its easier on the o'l puter