In a large skillet over medium-high heat, brown the ground beef, breaking it apart as it cooks, until no pink remains, about 8-10 minutes. Drain the fat.
Transfer the cooked ground beef to your slow cooker.
Add the taco seasoning and ranch dressing mix to the slow cooker and stir to coat the meat.
Add the black beans, pinto beans, corn, diced tomatoes with green chilies, tomato sauce, diced tomatoes, and beef broth. Stir everything together until well combined.
Cover and cook on LOW for 4-6 hours or HIGH for 2-3 hours.
Give the chili a good stir before serving.
Ladle into bowls and top with shredded cheese, sour cream, crushed tortilla chips, green onions, and diced avocado. Enjoy with extra chips on the side!