Dimensionalist
The Dimensionalist is an obscure form of Specialist Wizard introduced during the days of Advanced Dungeons & Dragons. It first appeared as an article in Dragon Magazine #229, and then reappeared with an official writeup in "Player's Option: Spells & Magic".
Though the Dimensionalist and Conjurer kits both focus on spells relating to the planes, it is in their particular area of expertise that they differ. Conjurers specialize in calling creatures from other realms to do their bidding. Dimensionalists focus on spells that directly draw energy from or manipulate the barriers between other planes - they are masters of teleportation, planar travel and spatial warping, amongst other aspects of extraplanar magic. They are not much for direct combat, but when it comes to avoiding trouble or circumnavigating obstacles, there's none better. It's all but impossible to keep a dimensionalist from going where they want to go.