The Battle of Bothawui in Star Wars The Clone Wars.
Context: The Republic had suffered heavy losses, and Anakin didn't have much left to defend against General Grievous, who was about to attack them. Despite Obi-Wan and Ahsoka insisting that Anakin retreat, he came up with a plan to take them down instead. Eventually, Grievous and his fleet arrive, and they start attacking. For a while, the odds appeared to be in Grievous's favor, and he was doing some serious damage. That was until Anakin revealed his hidden surprise, which consisted of a large number of AT-TE's hiding on the asteroids, and Grievous knew nothing of it until he had already passed them.

So once the time came, the walkers attacked his fleet from below, where his ships are most vulnerable, and quickly took out one of them in the process, and later did some damage to another. This allowed Anakin's fleet to retaliate and eventually destroy the entire enemy fleet. Right before the battle was over, Grievous escaped before his ship could blow up, and Anakin just happened to see him. So he then attacks Grievous, only for his fighter to give out on him before he could destroy him.
Why do I find this scene satisfying?
1. Simply put, the AT-TEs being out in space and then attacking the fleet. This has always been my favorite part of the entire battle because it's not at all something you would expect to see in space, and it's just so fun to watch, especially since it turns the tide of the entire battle.
2. It's a fine example of what should be a grim situation turned into an unexpected victory.
3. Although they don't speak to each other or see each other face-to-face because they aren't supposed to meet until Star Wars Episode III, we get a little Grievous and Anakin interaction. Which is something you don't see often because of what I just mentioned, and I can only think of 3 other times in the show that the two were on the same battlefield together. Even more interesting, according to Star Wars Legends, this battle was one that was not under Palpatine's control, so anything could have happened here since he had no influence on it.
While this is easily one of my favorite shows, I don't really have a high opinion of season 1 these days, but this scene is one that has
always stood out to me and one I still find myself going back to time and time again. Even if it has a rather unsatisfying ending.