Spike's made many friends over the years! He experienced his first crush in Rarity, he helped Fluttershy open up, he had some laughs with Rainbow Dash, he partied with Pinkie, he learned about being noble from Applejack, and when he decided to expand his friendships beyond the Mane Six, he helped Starlight reunite with her oldest friend, he started the peace between ponies and dragons with the help of Ember, he learned about dragonhood from Smolder, he was there for Thorax when no one else would which led to the reformation of the changelings, he let loose and had fun with the guys during his spare time, and found something very special within Gabby!

Of course, none of them can compare his close bond with Twilight, whose relationship is beyond explanation! Sure, he might've left some of his other friends behind for her — but he'll never forget the memories he made over the years he had in Ponyville — even the friends he made who didn't make it to the mirror, such as the CMCs, Cheerilee, Zecora, Little Strongheart, and others!