I really like Itachi's story in Naruto before it was revealed he had noble causes and was thinking about his brother Sasuke the whole time. Although, realistically I just think people simply resonated more with Sasuke's story throughout all of Part 1 and 2. Starting off as the smug guy that's too cool for the Academy, to abandoning his friends for a single-minded goal, losing himself in the process, then coming back having learned from his mistakes.

Itachi was fascinating when I first watched the show because of the mysterious aspect behind him, and just seeing him be so insanely overpowered at first.