1st Gen What did you evolve your Eevee into?

I replayed original Red and I got a-thinking, you can't catch Eevee in the wild nor is there a Daycare system yet, so you actually have to put a bit of thought into what to evolve it into. I chose Vaporeon because my starter was Venusaur and I was too lazy to use the advanced Rods. (Turns out, you also have the added bonus of having a strong Surf user that also learns Acid Armor.)

P.S. I taught my Vaporeon Ice Beam, making him Lance's arch-rival. :P

In Blue, I chose Jolteon. Used to have Blastoise on my team, so I needed that to back it up. :) In Pokémon Red, I ended up picking Flareon.

if I can remember I evovled my Eevee into Flareon in pokemon Yellow.

I evolved mine into a Flareon, because I didn't have a fire type at the time. I might have evolved it into Vaporeon, if I hadn't evolved my Magikarp into a Gyarados before then.

Flareon, although I would only use it when I had chosen Bulbasaur or Squirtle.

I got mine into a Vaporeon. Since there's ere only three evolutions, this one although not having a super diverse moveool had excellent defensive stats and was an alternative if you didn't want to run Snorlax. Plus I could use that Water Pulse TM from Misty. :P

I picked Jolteon, not for any reason, other than he looked cooler than the rest.

Always, always Vaporeon. Flareon had a horrible move pool in R/B/Y and Jolteon didn't have the greatest speed stat. At least Vaporeon had good defense and could use surf.

I had the most insane obsession for Jolteon when I first played Red. I'd draw pictures of Jolteon everywhere, make role play stories centered around Jolteon, I collected all the Jolteon merch, I even got my dad to paint a massive Jolteon on my bedroom door when I was 9. So I always evolved my Eevee into Jolteon. It became tradition in all casual play-throughs ~

I honestly don't quite remember, since I didn't start using Eevee that much until FR/LG. I'm pretty sure I'd usually evolve it into Jolteon, because I just always thought it had the coolest design. I don't really know how strong they were in the first two generations, but I'd usually evolve my Eevee, just to have the Pokemon. I'm pretty sure I've been through them all, but I imagine my first must've been Jolteon :p

As I reached Celadon City in Red/Blue, I thought it would be another boring city, but then a building (the department store) caught my attention. It took a while for me to realize that it was actually a Poke Mart, only bigger. As I found the three evolutionary stones, the first thing that popped into my mind was Eevee, and never would I have guessed that Eevee would be found in some random place (in my opinion).

It took a while for me to pick a stone, and I didn't know what Eevee would evolve to, I picked the Thunderstone, I imagined what Eevee would be like if it were to evolve to an electric-type Pokemon.
I made the right choice, because of that, Jolteon became one of my favorites until now.

I picked Joltoen. I didn't have any other electric Pokemon in my team then. Pin Missile was an added bonus as it was super effective against Psychic Pokemon.

Like others, I picked based on my prefences of other pokemon.

Flareon had no chance to be on my team, I LOVE Rapidash, Arcanine, and Ninetales. If I didn't pick any of those, I went with Charizard.

Jolteon is the only other electric line I like in gen one aside from Pikachu/Raichu. The magnet, pokeball, and ambiguous lizard were not my cup of tea. Though, unlike fire, water, and grass, I didn't NEED an electric on my team. If I did, I was always intrigued to find a pikachu in Viridian. So, I mostly picked Jolteon as an after-thought if I don't pick up a pikachu, oh, I do want an electric, let go with Jolteon.

Vaporeon is my favorite among all of the eeveelutions. Though, I do love Lapras and Seadra as well - Lapras being my second favorite Kanto pokemon overall. So picking between all of this great choices sometimes left out Vaporeon from my team. I mean, it's Lapras!

So, I would guess I chose Jolteon and Vaporeon equally, and rarely did I go with Flareon.

I ever choose to vaporeon, I like the pokemon with high speed stats, and ever start with squirtle and later caught a vulpix, is because ever evolve eevee to jolteon ^^

I evolved my Eevee into a Vaporeon on my Pokemon Yellow when I got it.

When I can I choose Flareon, I love water pokémon the most, but flareon is my favourite.

Jolteon. I always remembered needing an electric type filler, so with the Shock wave TM early, he became a pretty big threat in my Pokemon Team.

I used to choose charmander mostly as my starter in RB, and then caught oddish or paras to get a grass type, and pikachu for an electric type and then evolved my evee into vaporeon for a water type.