I like Jolteon better because it looks cool and it has awesome moves.
Jolteon is my favorite out of all the Eeveelutions. For some reason, I never saw Vaporeon's "beauty." I always thought that it looked quite ugly. Then again, I hated almost all Water types when I was younger. I don't know. Fish and jellyfish and... stuff with fins never appealed to me.
Jolteon just looks plain awesome. He's nice and speedy and can pack a punch. Plus, he's adorable.
Why make a poll with these two and not the other five Eeveelutions? At least include Flareon to complete the original Eeveelution trio. >_>
The reason why I only selected two is because I was only interested in finding out which one people prefered from these two .