Friendship is Magic tackles depression: the episode.
That was pretty stupendous in it's own right, and though I have a hard time ranking it amongst my favourites since cringe humour doesn't really do it for me, the great character moments, ending, and it's handling of depression/social anxiety/mental health issues makes this one stand out in a really unique way.
The background and little character bits in this were great. Like, I love this dialogue:

"You were fabulous!"

"Made me sit up proud like a corn stalk in august."

"You done good, squirt."
Which just encapsulates their characters so well. Rainbow Dash putting on a pair of sun-glasses and going all "Sup?" to be "casual" is also really awesome.
I give top marks to Pinkie here too. The "nailed it!" line was great, but I love her little head-bobbing smile while Spike is singing. That whole bit really illustrates how Pinkie's head is wired to a different frequency, and it does it with so little- one shot and a line. But it works because she seems to sincerely enjoy it and/or sincerely roots for Spike despite the awkwardness, perhaps having an extra fondness for obviously improvised music. She comes off as more supportive and caring because she isn't bogged down by societal standards, as opposed to insensitive and/or dumb, which I adore. Plus all the dialogue with her as a rabid sports fan and wanting to teach Twilight about it was really great too.
The last act with Spike is probably some of the show's best work, and is easily relatable. Like, just having him sit there blowing a feather because he has no will to do anything else is brilliantly true to life. And his inability to take pride in himself and what follows- it's a conversation I've been through, and I think a lot of people who've gone through it have as well. Capturing a lot of those subtleties takes this episode the extra mile.
I don't think it resonated for me that strongly because I'm more detached from Spike's character (despite my own experiences mirroring his), but this is a really excellent episode on rewatch (being able to handle the cringe scenes better), and easily my favourite Spike episode (I don't care much for JFS

).
Side Note: Ponyville winning the medal count didn't bother me, because that's not necessarily that far from real life.

The biggest country doesn't always win. Smaller nations can do quite well at the Olympics, beating out larger nations, through strategic investments in well-constructed programs.
