9. Qui-Gon Jinn
Since the majority of The Phantom Menace is dedicated to Qui-Gon Jinn, his death at the hands of Darth Maul is rather saddening to watch. Although the death itself is upsetting, a new angle has emerged which has made Jinn's end even more emotional than when the film first released in 1999.
During a roundtable discussion with his fellow writers and directors in an episode of Disney Gallery: The Mandalorian, Dave Filoni perfectly sums up why Jinn's death is one of the most emotional and pivotal parts of the Skywalker Saga. "What's at stake is really how Anakin is going to turn out. Because Qui-Gon is different than the rest of the Jedi, and you get that in the movie. He's fighting for Anakin, and that's why it's the Duel of the Fates. It's the fate of this child. And depending on how this fight goes, his life is going to be dramatically different."
So, according to Filoni, Jinn's passing is the key in the creation of the Empire and Darth Vader, since the father figure Anakin needs is abruptly taken from him, with Palpatine quick to assume that role. Therefore, Jinn's untimely death gives the end of The Phantom Menace more retrospective sadness than perhaps George Lucas initially intended.