Me too, The Starscream vs. Rainbow dash fight is the reason why i actually started watching MLP:FIM in the first place. other favorites included TMNT battle Royale, Mario vs. Sonic, Goku vs. Superman and even though it widely hated by most Peach vs. Zelda
I don't mind the fight scenes too much. It's just that the writing and pace is soooo egregiously baaaad. And then it takes itself super seriously with no self-awareness. Like, I watched the Kai series when it was rerunning on Nickelodeon a couple of years ago, and it's literally the same dumb thing over and over again: episodes of buildup telling us how the next baddie is so incomprehensibly powerful, so so everyone needs to train and get ready, then he shows up, and still no one is powerful enough, so we all have to stand around and gasp at how big this guy's pecs while we wait forever for Goku to show up because he's the only one that's allowed to do anything in this series, and then he wins. Rinse and repeat with Goku's brother (whose name I forget), Vegeta, Frieza, Dr. Giro, the androids, and Cell. The exact same thing, over and over again. Even when that green guy bonds with another green guy and they get more powerful, it amounts to nothing. When Vegeta becomes Super Saiyan, it amounts to nothing.
And if that's not enough, there's the Sensu Beans or whatever that basically make any kind of damage or injury sustained totally pointless, then there's the fact that if you die you can come back to life like it's nothing, and just... I can't stand it.