Pegacest, because Cloudchaser x Flitter is hot. Also Thunderchaser and Rumblechaser, because Cloudchaser x anyone is hot. Derpytop because it’s cute. Berrygate because they’re both adorable. Angelshy because Fluttershy deserves happiness, and she’s unlikely to find it with another pony because of her shyness. And of course the canon ones: Lyrabon, Mr. & Mrs. Cake, Shining Armor and Cadance, Cranky and Matilda, Twilight’s parents, Rarity’s parents, Bow and Windy, the Shys, Bright Mac and Pear Butter, etc.