Cut the chicken into pieces and place them in a 6 quart slow cooker.
Pour the sauce over the chicken and stir to coat.
Cook on high for 2-3 hours, or until the chicken is fully cooked.
Shred the chicken with two forks.
Stir to coat the chicken with the sauce remaining in the slow cooker.
Heat the pizza crusts according to the directions on the package.
Divide the taco chicken between the pizza crusts and spread it out.
Top each pizza with half of the shredded cheese, shredded lettuce, diced tomatoes and tortilla chips.
Serve with your favorite taco toppings.