Source: recipe booklet which came with a Crock-Pot Dip Master.

2 (8 ounce) packages cream cheese, softened
3/4 cup half-and-half
1 tablespoon finely chopped onion
1 clove garlic, minced
1/2 cup Parmesan cheese, grated
1 (10 ounce) bag frozen cut spinach, thawed and well drained
1 (13 ounce) can quartered artichoke harts, rinsed, drained and chopped
2/3 cup Monterey jack cheese, shredded

Combine the cream cheese and half-and-half in a bowl until well blended. Add the remaining ingredients and stir well. Pour the mixture into the Crock-Pot slow cooker. Cover; cook for 2 hours or until thoroughly melted.