Grand Theft Auto: Vice City
There are two Psychic shops, both located in Downtown Vice City. The words "Psychic" and "Readings" can be discerned in the shop. It is either fortune-telling or a palm reading center. It could also be a psychic emporium, featuring voodoo and/or occult magic.
Grand Theft Auto: Vice City Stories
Further details about the Psychic are mentioned in the GTA Vice City Stories' manual. They are mentioned under the name Celestial Psychics. Their service number is 1-666-555-5555 and they charge $9.99 per minute.
It is also notable that 666 is the numeric symbol of Satan.