Last time, I covered the strange mystery that is an Eevee. I will be more specific on how you can get Eevee’s “Eeveelutions” through various games. Through the classic games, a Water Stone would turn Eevee into Vaporeon, the one with lots of HP. A Thunderstone will turn Eevee into Jolteon, and a Fire Stone, into Flareon. To turn Eevee into Espeon or Umbreon, you need to increase its happiness. Before time-based Pokemon games came out (time is the deciding factor for this evolution), you would need a Sun Stone for it to turn into Espeon, the sly, powerful, Psychic-type, or Umbreon, the well-rounded Dark-type.
In games like Pokemon Mystery Dungeon, you would need a Solar or Lunar Ribbon, and of course, feed your Eevee some gummies for its IQ to increase. More specifically, in games (starting from Pokemon Diamond and Pearl Versions) you would need to evolve Eevee between 12pm and 12am; this is considered daytime in Pokemon. On the other hand, 12am to 12pm is considered night time; it’s required you get your Eevee happy enough to turn it into Umbreon. To get the two recent forms, Leafeon and Glaceon, you would need to also make it happy, but you must be near certain stones. Since there are no places with stones in Johto/Kanto (Heart Gold and Soul Silver Versions), it’s impossible to get a Leafeon or Glaceon there; you may need to trade it from Diamond or Pearl version.
In Diamond/Pearl, there is a Moss Rock somewhere in Eterna Forest (around the second or third gym). Level up your Eevee around there so it can evolve; if its happiness is enough, you can just touch the rock so Eevee will turn into Leafeon. In the Pokemon Black and White Version, you will need to go to Pinwheel Forest, also around the second or third gym). The same concept is true for Glaceon. The Ice Rock, found in Route 216 (D/P) or by travelling deep into Twist Mountain (B/W) can turn your Eevee into Glaceon.
Leafeon and Glaceon are Sinnoh-specific and onwards; you cannot trade it back to previous versions (it’s impossible too, since Diamond and Pearl were the first Pokemon games for the DS). There are some people that say that they like the first few “Eeveelutions” of Eevee and that the recent “Eeveelutions” ruined it for them; I don’t have an opinion on the subject. If they keep on coming, I just keeping on catching, or breeding, or whatever it may be. Eevee fans will still be loyal, no matter how many “Eeveelutions” there are. Let’s count: We already have the Normal-type Eevee, the Water-type Vaporeon, the Electric-type Jolteon, the Fire-type Flareon, the Psychic-type Espeon, the Dark-type Umbreon, the Grass-type Leafeon, and the Ice-type Glaceon.
If I had to make a prediction, the next one would be Ground- or Steel-type. The creators are really running out of ideas (and elements!); they will really need to pull out all the stops to make the next “Eeveelutions” of Eevee well worth the effort. On the topic of my favorite, I would have to say Umbreon, since it was the first “Eeveelution” I really got to interact with by playing with it in Pokemon Coliseum; plus, it is the most well-rounded of the 7.
The second favorite is Glaceon, since a good friend of mine got me a Glaceon plush for my last birthday. There’s an “Eeveelution” for every cause, no matter how small. Maybe I should stop putting “Eeveelutions” in quotes, it’s already a term that might as well be in the Pokemon dictionary…