In a large skillet over medium heat, brown the ground beef until fully cooked, about 5-7 minutes. Drain any excess fat.
Add the taco seasoning and water, stirring to combine. Simmer for about 5 minutes until the sauce thickens.
In a large bowl, combine the chopped romaine lettuce, cherry tomatoes, shredded cheddar cheese, black beans, and corn.
Add the cooked taco meat to the salad mixture and toss gently to combine.
Just before serving, add the crushed Doritos on top of the salad for crunch.
Drizzle with ranch dressing and salsa, then toss lightly to coat the salad evenly.
Serve immediately for the best texture. If preparing in advance, store the salad and dressing separately and combine just before serving to keep the Doritos crunchy.