any ideas?

You shouuuld get Y, mega charizard Y increases the sp. attack and it gains the ability drought that increases the power of all the fire type moves while charizard X only turns into a dragon and is more focused on attack i think... also mega mewtwo Y gets the ability insomnia that prevents it from sleeping and its sp. attack increases, while mewtwo X is more focused on attack and gets the ability steadfeast that increases its speed when it flinches. (that usually never happens so for me that's quite bad) And for the legendaries Yveltal has awesome moves and a really cool design and it's strong and never actually faints. Xerneas attacks isn't so good and it isn't as strong as Yveltal and faints quicker. (i have pokemon Y and have Xerneas in my team, and I don't like Xerneas so much) Also you get mega Aggron~ c:
There you go~ The differences between x and y. (so go and get Y now!) :D

Thanks Waffle Ninja XD

Seriously tho, I got so da.mn dissapointed with Xerneas you don't even want to know. ;n;

Y version because it has more good mega evolutions and better exclusives. Do you know what you can do with Charizard Y that you can't do with Charizard X? Teach it solarbeam! Then have it mega evolve whenever you want to use solar beam, and the drought will instantly charge the solarbeam, so it doesn't take 2 turns to hit. And there's also the increased special attack stat, which will make solarbeam (with base power of 120) even more powerful! You won't really need to fear water types anymore, just the ones that have partial resistance to grass due to a second type. So you can easily KO Blastoise and Greninja!

By what you can do with charizard y that you can't with x, I meant the drought/solarbeam combo, not the solarbeam by itself.

Cool mega evolution exclusives:
-X version
Mega Tyranitar
Mega Charizard X
-Y version:
Mega Charizard Y
Mega Aggron
Mega Houndoom

I'll post them ASAP! oUo