Even if it were, it's worth suggesting twice for it's brilliance XD
Best Twilight Sparkle moment--
I vote as well for the scene in Return of Harmony part 2 where Twilight reads all the returned letters from Celestia and breaks the spell Discord had over her.
I vote for the moment when the Apple (extended) family loses the race against the Flim-Flam brothers and have to pack up to leave. AJ letting them all know that they won and it's okay to drink their cider... I get all misty-eyed.