The only differences that I know of are X gets you the Legendary Pokémon Xerneas (Fairy type, which is the new type introduced in these games.) and you can catch Aron. Y gets you Yveltal (Dark/Flying type) His signature move is Oblivion Wing which is basically a cooler looking, more powerful Giga Drain. You can also catch the Pokémon Larvitar.

Only reason I got Y was for the Mega Charizard thats still Orange :lol

Oh Kickback! If you get either before January 14, youll get a free pokemon!

It boils down to who you think looks cooler. Xerneas or Yveltal. Aside from a few Pokemon being exclusive to one version (Aron, Houndour, Clauncher, and Staryu in X, or Larvitar, Electrike, Skrelp, and Shellder in Y), they're very similar.

However, the now defunct slogan of the franchise, "Gotta catch 'em all" does need both games to accomplish.

Okay, finished Empoleon (Insert battle request here), and now to work on Porygon.

Now then. Should I run a defensive Porygon2 or an offensive Porygon-Z?

Nope. No one on my end is ready. The Lucky Egg helps. but it's still kind of slow going.

Aww...This Salamence is causing me so much grief. And I've never gotten to fight it :lol

Why are you so concerned? Rarity will probably destroy it.

That's not a fair assessment, though.
Rarity destroys everything.

But Ice Be-
Oh.

Don't worry, I won't bring Rarity against it :p

Reshiram training is nearly complete. He's up to level 94.