In a large, deep skillet or pot over medium-high heat, brown the ground beef with the diced onion until the meat is cooked through and onion is softened, about 6-7 minutes.
Add the minced garlic, chili powder, cumin, paprika, salt, and pepper, and cook for 1 minute until fragrant.
Stir in the diced tomatoes with green chiles, tomato sauce, and beef broth, then break the spaghetti in half and add it to the pot, pushing it down into the liquid.
Bring to a boil, then reduce heat to medium-low and simmer uncovered for 12-15 minutes, stirring occasionally, until the pasta is tender and most of the liquid is absorbed.
Remove from heat and stir in the shredded cheddar cheese until melted.
Serve topped with sour cream and crushed tortilla chips.