Sun/Moon were easily the better game to me. X/Y are the worst games to in the Pokemon series to me and it's not even close, meanwhile, Sun/Moon were the best Pokemon games to me since Emerald.

Sun and Moon have a much better singleplayer, plot, and it's much more interesting (no gyms, islands, riding Pokemon). Overall is also a better game.

But I'll say XY has better gameplay. Mega-evolution (as silly as it was) changed gameplay much more, and in a better way, than Z-moves. EV training (Horde Battles > Unfair double battles) was much easier in XY. Speaking of which, while I think Totem Pokemon are a worthy substitue of Gym Leaders (as a challenge), calling for help is a bad mechanic. Specially when you're trying to catch Pokemon.

Most of my complaints come from the competitive side of things, which GameFreak tried to shake up with some new abilities and Pokemon, but in the end they made some annoying mechanics and a super unbalanced move. Like I said though, Sun and Moon are better overall, since most of the gameplay is still Pokemon...

Sun and Moon have something going for it though: Actual characters. Heck, as a silent character, Sun and Moon's protagonist is more interesting than the whole cast of XY.

Hau alone undermines that satatement. Hau alone is worse than the whole cast of the whole franchise. 

I feel like Hau was supposed to be the comedy relief of the game, but he was not funny enough to fill that role, plus he was wayyyy too happy in moments when he should't have been. The player character is funnier, even if it is just because he kept one expression throughout the whole game.

I don't particularly think theres been good rival/friends in the franchise since gold/silver. The whole cast of XY was pretty forgettable. But no one got on my nerves more than Hau. He comes off as annoying, not really funny in the least. Loved Lillie and Gladeon tho. 

sun and moon for some reason

I agree with the lack of good rivals, but I have to make a really big exception in the case of N in Black/White. That was a fantastic foil and anti-hero. Sun/Moon cast is better in general than X/Y, with the exception of AZ, which is a great character.

I do agree that they didn't convey the threats of the Ultra Beasts well at all, big disappointment for me. I found it annoying that the Ultra Beasts were reduced to the status of random encounters in the wild... And Sun and Moon had so many cutscenes, but no cutscene that shows Ultra Beasts threatening other people? That's my only letdown with the story basically.

We have that amazing cutscene where the Ultrabeast attacks the kahuna and Tapu Koko has to fight it, and then... nothing really like that. The fight against corrupted Lusamine was also a big letdown. Once again, we get a really impressive cutscene showing us the fusion between her and the UB, and I was thinking "Am I going to have to fight a human-pokemon hybrid? This is great, this looks something out of a Shin Megami Tensei game or the sort!" and then she just uses her pokemon team. Then why did you fuse at all!? What's the point? Why did you tease us like that?.