Blend together the sour cream, mayonnaise, and cream cheese. Mix in the artichokes, spinach, cheeses, Worcestershire sauce, garlic, salt, pepper, and cayenne pepper. Taste and add more salt and pepper to taste.
14 ounces artichoke hearts, 10 ounces frozen chopped spinach, 1 cup sour cream, 1/4 cup mayonnaise, 4 ounces cream cheese, 1/4 cup Parmesan cheese, 1/2 cup mozzarella cheese, 2 garlic cloves, 1/2 tablespoon Worcestershire sauce, 1/2 - 1 teaspoon salt, 1/8 - 1/4 teaspoon black pepper, 1/4 teaspoon cayenne pepper