Preheat oven to 350 degrees F. Brown ground beef over medium heat, in large skillet. Add taco seasoning and water. Bring to a boil, reduce heat to low and stir in cream cheese until melted and completely blended. Allow to cool to room temperature.
Prepare shells as directed on box, being sure to not over-cook. Drain shells and place on baking sheet so the don't stick together.
Use 1 cup of salsa and spread evenly over the bottom of a 9 x 13 inch baking pan. Reserve remaining salsa. Using a teaspoon, carefully stuff shells with taco beef mixture. Place each shell in pan, atop salsa. Drizzle the taco sauce evenly over the shells.
Cover the baking dish with foil and bake for 30 minutes. Remove from oven, spread shredded cheese over shells and bake, uncovered, for 15 more minutes. Remove from oven, garnish with green onions and remaining salsa, serve immediately.
For some added crunch and fun, add a handful of crushed nacho chips on top of the shells, prior to adding the cheese.