season 1:
Dragonshy: Fluttershy flipping out and cutting that epic promo on the dragon.
Bride Gossip: That whole scene where the poison joke kicks in and Flutterguy appears. Funniest thing ever when I saw it the first time.
Sonic Rainboom: Yay! scene
A Dog and Pony Show: This is whining!
season 2:
Lesson Zero: "Clock is ticking, Twilight!" scene
May the Best Pet Win: The Find a Pet song
The Mysterious Mare Do Well: Rainbow feeling lonely on the cloud scene.
Read It and Weep: The scene where Rainbow realizes she loves reading and says "I'm an egghead!"
Putting Your Hoof Down: When Fluttershy cuts another legendary promo on Pinkie and Rarity. Edgy, I know
Hurricane Fluttershy: All of it, but especially the end.
A Canterlot Wedding: This Day Aria
Season 3:
The Crystal Empire: The scene where Twilight and Spike find Sombra's enchanted room or whatever. The moment where MLP took a really dark turn (and not just in tone kek jk tbh the show didn't go downhill until later )
Sleepless In Ponyville: When Dash takes Scoots under her wing.
Magical Mystery Cure: >tfw A True, True Friend starts
idk about seasons 4 and 5. Definitely include the end of Testing, Testing 1, 2, 3 when all of Ponyville teams up to help Dash out. Ending of Filli Vanilli. I'll probably think of more later