Usually, Intelligence is used by Wizards and Wisdom by Clerics. A Wizard (Mage, Sorcerer, etc) with high Intelligence may have more spell points, more spells/day, ect depending the game, Wisdom is the same for Clerics (Priests).
An high Wisdom help the character even against mind-controll spells, usually.
In some games, Paladin with high Wisdom and Rangers with high Intelligence can cast spell when their level is high (9th, 10th or higher).
EDIT: awesome avatar!!!!!