My favorite Eeveelution? I'll just post then in order..
1. Jolteon- My fave by far. He looks cool, is a good battler, not to mention he's Electric. What's not to like?
2. Espeon- One of my best pokemon in both Crystal version and Collosseum. Very cute as well, and I've always sorta liked the Psychic type.
3. Umbreon- Umbreon was my favorite Eeveelution back when G/S was first released. Sadly, I never owned one until Collosseum came out.
4. Vaporeon- My very first Eeveelution, from my very first pokemon game, Yellow version. Not bad looking, but not as cool as the first three. Its in the middle.
5. Leafeon- Augh! Why did they name you Leafeon?! I've been hoping for a Grass Eeveelution for years, and this is what they give me? I could have come up with 10 better names than that! Oh well, Leafeon's not bad otherwise.
6. Flareon- I only like this one because its cute. No other reason. Its not very good, IMO. But that's just me.
7. Glaceon, the whole point of making this thread, comes in last. I don't like its appearance at all (I dunno why, I think its head is just a but big) and I really didn't want an Ice type Eeveelution. Make it Steel, next time, Gamefreak.