Personally i’d say XY and gen 6 in general, mega evolutions are excellent and they made an actual effort putting lore into the games (plus i’m french so i may be biased because kalos), ORAS were imo the best remakes ever and are exactly what a remake should aim to be.
Grew up with Gen 3 and 4, and those have sentimental value with me; spent a lot of time trying to complete the Pokedex. I want to say it’s been going downhill since gen 6, but I think that might just be me being grumpy and old. :P
IMO gen 6/7 was the peak, it all kinda became garbage from there, especially with dexit and DLCs (thought its also the point where i stopped playing the games due to lack of emulation)