Maybe Quest Buy; it's just done really well and actually turns out to have a lot of important stuff in it despite seeming like filler at first (I didn't even like it the first time I saw it because of Ludo appearing twice in one episode). The jokes are all pretty great too.
Bon Bon is probably the strongest whole episode; I'm not sure that it's my favorite of the series but it beats Storm the Castle and St. O's.>LEAST FAVORITE EPISODE
Banagic. No explanation needed at this point.>OVERRATED EPISODE
St. O's. Too short of a runtime, the individuality stuff has no subtlety at all even for children's TV, was too obvious what would happen because of Star's freakouts in prior episodes (they could have at least tried to make the brainwashing aspect the school's dark secret or something, rather than literally saying they're going to suck the individuality out of the group of new students within seconds of their arrival), despite the episode being a couple minutes short the crystal that disables the use of dimensional scissors is easily destroyed in 5 seconds. Miss Heinous should interest me but still doesn't.
It's still okay, there's some stuff to like about it, but it's kind of disappointing.>UNDERRATED EPISODE
Lobster Claws. The humor's good, it actually first introduces the monster/Mewman conditions on Mewni, uses Ludo in a slightly more unique role for season 1, it even seems to foreshadow Eclipsa's magic/the dark side of the wand. But a few people who bitched about every episode of the show early on made it out to be THE WORST and idiots continue to repeat it even now. It adds to the DEEP LORE in a low-key way and is better than probably half of the segments out there at least.