Preheat the oven to 350°F (175°C).
In a mixing bowl, combine sour cream, mayo, cream cheese, drained spinach, artichoke hearts, garlic, and ¾ cup of parmesan cheese. Mix until smooth.
Grease a baking dish (around 8x8 inches or a glass pie dish works well).
Pour the mixture into the greased baking dish.
Sprinkle the remaining ¼ cup of parmesan cheese on top.
Bake for about 20 minutes, or until the dip is hot and bubbly.
Serve warm with crackers or bread. Enjoy!