I have only three Eeveelutions that I use: Vaporeon, Jolteon and Espeon. Vaporeon is a bulky that can withstand several super-effective special attacks and dish out some nice damage with STAB Surf and dragon coverage with Ice Beam/Blizzard. I use my Espeon mostly as as Screen/Reflect set-up and Wish-passer (Along with STAB Psychic). Jolteon is my SubPasser: Use Substitute, fire off charge beam and hope for a boost, then Baton Pass both the sub (if it's still up) and the boost to Sp. Attack to Mewtwo. It also knows Hidden Power: Water to catch Rock and Ground types off guard.