The season six episode 'The Lost One' is legitimately one of the greatest episodes from The Clone Wars and isn't talked about nearly as much as it should be.
Makes the mysterious character of Sifo-Dyas even more compelling, while also making the Jedi's discovery that Dooku was Darth Tyranus all along terrifying to watch unfold.
Brilliantly builds on both Episodes I and II, and makes the events of Revenge of the Sith somehow even more sinister. Such an underrated episode with incredible storytelling.
Peter visiting May’s grave and then we get a flashback of that cliffhanger from Homecoming and we see a heartfelt conversation between the two of them would hit so hard emotionally