If you want a gecko that you don't need to feed live food, i'd suggest researching Crested Geckos.
They can be kept on something called Crested Gecko Diet which has all the goodness they need in it, you just add water.. it is, however, a complete diet so you shouldn't supliment it.

As the others have said, it is important to feed Leopard Geckos live food as they need the nutrition from gut loading, they are fussy and to be honest, i think it does them good to hunt their food.