One of the season's funniest episodes.
A Dog and Pony Show is a near-perfect display of the series' humourous charms. Between character quirks like Spike's barely-restrained hunger for gems to clever writing like every interaction between Rarity and the Diamond Dogs, the episode has a lot to offer.
The energy starts almost immediately, with an entertaining cold opening starring the hammy Sapphire Shores. Of course, Sapphire never appears again, but her over-the-top appearance here is wonderful. Sapphire Shores has the kind of over-the-top performance that includes singing random words for no apparent reason, and it's purely delightful.
A lot more of the entertainment value comes from the personalities of the characters. Second to Rarity, the most notable character of this episode is Spike. His adoration for Rarity is as cute as it is funny, and some of his lines in that regard are in fact very sweet. Many more of his lines, however, are more humourous, from getting distracted by gems, which he labels "delicious", to his daydreams of saving Rarity.
The third most prominent character is Applejack, who has some of her best writing of the season in this episode. Moments like her reactions to Spike kissing the air in his daydream and her response to having a rope put around her muzzle really show her off at her best, and her confidence throughout helps her best qualities shine.
Of course, the most prominent character of the episode is Rarity, and she's mostly fantastic here. Her scenes with the Diamond Dogs are very cleverly written, and her creative techniques in resisting the Dogs are endlessly entertaining. In particular, the iconic whining scene is hilarious. However, this is still season 1, where these friends don't quite fully understand each other. Rarity is the butt of some of the episode's jokes, especially when her friends imagine a silly exaggeration of her aversion to dirt. These thought bubbles are definitely funny, but they are so at Rarity's expense. Similarly, Rarity's prissy attitude seems to still draw a little too much from some of her worse character traits, though many of her good qualities do shine through.
This is an energetic, clever, and very entertaining episode. From cute exchanges between Spike and Rarity to Rarity's hilarious antics, it's another very entertaining MLP episode.