Gave each clone their own identity
The creators of The Clone Wars didn’t waste any time unveiling what would be one of the best elements of the show and that would be giving each clone his own identity. In the films, the clones are just mindless soldiers who are given no character development whatsoever. They were made to be dispensable and that is how they are used in the film.
In The Clone Wars they are on a mission with Master Yoda and he tells them that while they may look the same on the outside, they are all different in the Force. This inspires the clones to create their own looks and take on unique nicknames that separates one from another. Suddenly, each clone has his own unique personality and traits and we begin finding ourselves caring about these faceless soldiers.
To accomplish that was a huge feat by the creators of this show and a truly inspired idea. To put a face to every clone and make us care if they fall in battle was something unforeseen that kept us emotionally invested in this show.