I don't know who was nuts enough to think Discord, Spike, and Big Mac would make a great team back in Season 6, but whoever it is, thank you! Big Mac, Spike, and Discord all act like they knew each other for years, even though this trio only formed after Discord officially became a part of the Guys' Night team. They play off one another through their actions, responses, and emotions, creating great chemistry with one another.

Speaking of chemistry, Spike and Discord are outstanding in their best outings of the season thus far (and maybe of the show, too, once it's all finished). Discord's cynicism towards H&HD, and love in particular, plays off spectacularly with Spike, who's very optimistic and refreshingly snarky. To think that only a few seasons ago, Discord was one of his enemies, but from the way they talked to each other and knew each other so well, you'd think he was closer to Discord than Twilight. How they interacted with one another was among the multi-dozens highlights here, such as Spike criticizing Discord's pessimism to Spike intentionally teasing Discord for possibly having a crush on Fluttershy to Discord ignoring Spike's sappy romantic poem about Rarity. They know how to get under each other's skin without crossing the line, making their teasing all in good fun rather than mean-spirited.

One of the season's biggest improvements — the dialogue — really shines. Every line's so organic, even when it's somewhat expository, gelling together. Every line oozed with personality and passion, whether it's from the O&O squad or the CMCs. Confalone knows how when to have them talk or act and keep them all in character. Even Big Mac isn't confined to that "Eeyup!" gag, varying his emotions or telling Discord to "EeWAIT!" The dialogue allows for not just some amazing comedy, but also some heart. More 'bout the latter later.

The comedy here is golden! Every joke landed perfectly, from the dialogue responses to the satirically cheesy love music playing in the background as Big Mac rushes to Sugar Belle to Big Mac's drinking a barrel-load of cider to Sweetie's "Please say no." Spike's deadpan to Discord as an anti-romance cynic is one hell of a comeback, and that jab towards the greeting card industry by Discord is too funny.

Oh, yeah…

>Lyra and Bob Bon sharing H&HD bond & gifts

>best friends

Riiiiiiiight. XP

The CMCs were also fantastic here. All season so far, they've been at their A-game. The episode recognizes them as kids, but doesn't make them so obnoxious. They were right to wonder where that mysterious pie came from and search high and low to find him. But the and does a nice swerve: They may not have found that actual special somepony for SB, but had a magnificent time together, anyway. Sweetie's small speech at the end had quite a lot of heart in it.

Speaking of heart, as hilarious as TBUBD is, Confalone balances it perfectly. Big Mac's sadness was somewhat over the top, but treated with the respect it deserves. His romantic feelings with Sugar Belle feel genuine, and you can tell by how he talked about the small stuff to Skelenor, like how Sugar snorts and wiggles her nose when she giggles (something that @Nyactis Mewcis Catlum pointed out a while ago in a status). Big Mac doesn't talk much, so when he does, you listen. After they cleared up everything, it was all okay again, and they had a great end to Hearts & Hooves Day.

Discord's revelation of finally believing in romance works perfectly and marks my moment of the season so far: revealing to damage her wagon wheel. Why? 'Cause he confirms to us he believes in love and figured out how to get them back together while remaining in character. He's still a jerk, and his advice to BM (long with Spike's) really stinks. But at the end, he retains a heart of gold and does the right thing, even when he's spoiled for Ogres & Oubliettes. Somehow, he predicted what Big Mac was going to do next, but given he's the Lord of Chaos, it makes sense. Really shows he cares for him as a friend.

Derpy was great in her role as mailmare.

As Discord counted the types of tea he loved, Top Draw lowered the audio quality of de Lancie's mic to match the sound one would hear from the old-school TV. Really masterful editing that helps enhance the joke. (The same scene from the leaked version, BTW, has the same audio quality as the rest of the ep.)

Oh, and it has two morals, each executed masterfully:

1. "Don't assume. Communicate with your friends, and everything will work itself out."
    
2. "Don't be afraid to openly admit your feelings. Those who care for you will listen and understand." This one is my favorite of the season so far, because it's so relatable to everyone.

When I first watched it in December, I watched a treat. Seeing it completed gives it such a fresh look, and it still holds up excellent. The Break Up Break Down isn't just the best episode of Season 8 so far, but one of the ten best of the show altogether, as well.