Star Wars Galaxies?

Shredmywheat

Where do you find Darth Vadar and Luke Skywalker in SWG?

Xaviel

Darth Vader is on the planet of Naboo inside the Emperor's Retreat which is a POI that you should be able to find on your Naboo Map.  If I remember correctly the closest city is Keren but it's been a while since I played that game.  Also, in order to get inside the Emperor's Retreat you need to complete a series of quests that are actually kinda fun and will give you some decent rewards at the end.  Both Darth Vader and the Emperor are inside.