Cook crumbled hamburger until no longer pink. Add taco seasoning and water and cook according to the taco seasonings directions.
Put Doritos on four plates (as little or as much as you like). Top with finished cooked hamburger. Sprinkle with cheddar cheese (again, as much or as little as you like). Top with shredded lettuce and tomatoes. If there are other taco toppings you like, add them too.