Brown beef in a large skillet over medium-high about 8-10 minutes until fully cooked, breaking up with spoon; drain excess fat.
Stir in taco seasoning and 1/4 cup water; simmer 2-3 minutes until thickened.
Transfer beef to slow cooker; stir in cream cheese, black beans, pinto beans, corn, tomatoes with chiles, cheddar, Monterey Jack, and salsa.
Cover; cook on LOW 2 hours, stirring every 30 minutes, until cheese melts and dip is smooth and creamy.
Switch to warm for serving; stir occasionally to keep smooth.
Serve with chips; offer sour cream, green onions, and jalapeƱos alongside for topping.