I like how Glaceon is kinda broken in Pokemon Brown. It learns Surf and like, some other pretty good special move too that isn’t normally part of its movepool.
I’m currently using Vaporeon in Dark Violet and it’s doing very well for itself thus far :3
I used to love using Flareon in vanilla Fire Red, it’s actually quite good if you invest in the Flamethrower and Shadow Ball TMs, with Shadow Ball running off of Flareon’s superior Attack stat in gen 3.
Jolteon is my second-most-used after Umbreon, and probably the mon I’ve used the most in terms of filling the “speedster” role I always go for on my teams. Its base 130 Speed has come in clutch so many times, and it was a member of the first team I beat Renegade Platinum with.
Sylveon I’ve used a few times, including on my first-ever Y team.
Leafeon it’s been way too long since I’ve used it.
Espeon is my second-favourite Eeveelution and I was using it in a Sacred Gold playthrough I never finished. Def gotta use it again sometime - it outspeeds Whitney’s Miltank and gets Calm Mind in time for the fight, resulting in an easy sweep.