I think this is the standard list:
Translabyrinthine Approach: Often shortened to translab. Goes in behind the ear, takes out parts of the hearing and balance organs and cuts those nerves. This sacrifices hearing , but gives a good view of the facial nerve and clear access to the tumor, and the brain is not moved. Developed and preferred by neurotologists, who are otologists (ear doctors) that specialize in nerve related issues and surgery.
Middle Fossa Approach: Goes in over the top of the ear, avoiding the hearing apparatus, but requires moving part of the brain aside (retraction). The top of the bony canal is removed, exposing the tumor and nerves, and the tumor can often be removed without damaging the hearing nerve, thus preserving hearing. Gives a fairly good view of the facial nerve, especially with smaller tumors.
Retro-sigmoid Approach: Comes in from the back of the head, along side the brain, which is moved aside (retraction). Gives the best view of the brainstem and CP angle, and is the traditional neurosurgeon approach. Often used on larger tumors, especially if they are in the CP angle or pressing on the brainstem. In some cases the hearing nerve can be preserved, though the view of the IAC canal is not as good.
Steve