Easiest game to catch shiny pokemons X/Y or Ruby/Sapphire?

Which game is easiest to catch shiny pokemons, Ruby/Sapphire or X/Y?

I'd say Omega Ruby and Alpha Sapphire. The DexNav is much easier to use than PokeRadar which can be a pain to chain on. Those are really the only differences in shiny hunting between the two games.

Now if you meant the original Ruby and Sapphire then X and Y would be easier. RSE have no way at all to increase your odds.

Also a fair few people run into unexpected shinies in Friend Safaris on X/Y.

There's no way to catch shinies easier in R/S. XY is far easier as there: Chain Fishing and utilizing the poke radar (the chain thing is most frustrating as if you break the chain, the odd will revert back)