Pokemon 3ds

Hi so i have a 3ds and finished only pokemon sun already,
my question is which 3ds pokemon game should i purchase next?
(sorry if this is not the right place to ask these questions my bad)

Ultra Sun, Omega Ruby, X, or even the DS versions Black, Diamond?

My personal opinion would be:
X and Y are the best experience you can have on 3ds, now.

Ultra Sun/Moon are awesome, but if you just played Sun recently, then X and Y will have a great story and a big world for you that you have not seen.
Ultra Sun/Moon only have a few extra features, but X and Y have a whole different fun world to play while you trade and battle online.

After that, I would suggest the Omega Ruby game, it has a lot of PKMN to catch and has cool new stuff, but I would say that X and Y have more interesting things to play with first. For me the Emerald era remakes are more something to fall back on after you have seen all the stuff the newer games have to offer.