What I am writing he is my opinion and is in no way, shape, or form fact and should not be taken as such. So first this generation did a lot of things right and is probably going to be remembered as one of the best generations of Pokemon and I will explain why I think that is, the first thing is we had the most serious Ash who was much better at battling then his other incarnations who wasn't constantly treated as the butt of a joke. Ash's Pokemon themselves were probably the strongest he had with Noivern and Talonflame facing the legendary Pokemon Zapdos and Moltres, Ash-Greninja who could stand against the Champions ace, and Goodra who is his first Pseudo-Legendary. The battle animation was epic fully showing off the full skills of Ash and his Pokemon accentuating how much better they were then previous generations. Serena herself was the best girl for shipping with Ash no one should be able to deny that, though they still will. Alain in the Mega Evolution specials was probably one of the most epic rivals we have had including Paul and Gary Oak. The team flare arc was amazing and was a great way to finish the series.
Of course nothing is without its flaws and as far as I'm concerned XY had some big ones, first up Ash seemingly traded in his personality for his battle skills because as far as I can tell he is now basically rarely sad, annoyed, angry, hot-headed, or confused and seems to be mostly determined, or happy with the exception being in the Greninja arc after Wulfric, which in my opinion was taken a bit too far and seemed exaggerated, I can understand why this epic Ash who wins nearly all of his battles and is not treated as a joke is great, but its not the Ash I like so I dislike the lack of personalty despite his skill. The Pokemon themselves like Ash while awesome seem to lack a lot of personalty of the earlier ones such, which again I can understand for those who like epic battles with the hero wining but its not the personality filled Pokemon I like. Serena herself has a lot of problems such as her goal Pokemon Showcases, while I understand that its is relatable how she took her time looking for her goal what with people in real life taking their time to find their goals it is not entertaining to watch, I don't expect it to be instant but if they had her find her goal quicker they could probably have spent more time fixing other problems, such as her rivals being boring and not offering any actual challenge by developing and showing them winning against Serena more, and they could have also spent time show her slowly changing her strategy when losing and such not making it look like the writers were keeping her from losing and another problem is most of her time not spent of Showcases was spent of her crush show off little of her own personalty, Clement has a problem in that after the gym battle he was pushed off to the side and left to stagnate, and Bonnie was just their for the marriage joke and Squishy. Alains problem was that most of his character was in the specials as in the series his rivalry with Ash was pretty sudden while normally we have a whole generation to see them interact so we can get heated about he rivalry, and with the rest of the rivals they weren't rivals but people they meet on their journey that they had to face against to reach theirs goal.
My final opinion on XY was that it was mainly for the older audience because they will enjoy the amazing actions scene, the lack of humour, and the shipping, so for those who like those things its probably the best generation, while for those like me how liked the humour and character interactions it was great but could have being better, and member this is my opinion not fact.