Place all ingredients in a medium saucepan over medium-low heat.
Cook, stirring constantly, until all ingredients are thoroughly combined and the cheese is bubbly, about 5 minutes. Serve with tortilla chips, bread cubes or vegetables.
For Crockpot Chili Cheese Dip:
Spray the bottom of your slow cooker with non-stick cooking spray (or use a liner). Place cream cheese cubes in the slow cooker. Smoother them with chili, then salsa, then the cheddar cheese.