Eva/Molly gets a special mention from how she started off as an inexperienced pilot to a skilled one. Then there's how she won Oban. She was in dead last, the newest pilot, and had underwent a Heroic BSOD. However, even with all of that, Eva/Molly managed to win the last race. And thus getting the entitlement of becoming the next Avatar.
The second race against Toros. Earth Team star-racer goes whoosh! Toros's star-racer goes crash! Nobody can believe their eyes!
Eva/Molly's epic Calling the Old Man Out moment with her father, Don Wei after he FINALLY figures out she is his long lost daughter.
The theme song Never Say Never, to the point that even people who didn't particularly care for the show admit to tuning in just to catch it.
There's a bit of soundtrack that plays during the episode "The Origin of the World" right after the race begins and the racers get their first clear view of the racetrack. It is awesome and sets the mood very well.
Each of the alien racers have their own catchy theme musics, which could be hard to fully hear amongst the action-packed racing.