>>283095447
Xros Wars (Fusion). Digimon always thrived on an ensemble cast, with each season's criticisms usually revolving around how effectively or poorly it executed on that element. Xros Wars was the first season to start walking back on the premise, where several main human characters either have no digimon partner or have one that does not fight. This means they get very little character development throughout the series compared to the main gogglehead. Secondly, Xros Wars ditched traditional digivolving for its fusion mechanic, which wasn't as popular and got dropped in the subsequent season.
After Xros Wars, they went even more unconventional with App Monsters, who aren't even real digimon and don't get featured in the games now. They went back to their roots trying to reboot Adventure, which was mostly criticized for just being a worse version of the original that ruined the pacing and focused too much on Taichi instead of the ensemble cast. Ghost Game was another unorthodox story, with more focus on horror and mystery than just battling and adventuring, and suffered heavily in its development leading to some of the overarching plot threads being rushed or dropped towards the end with most of the show being very episodic.
Beatbreak is only just now airing, but it seems to have promise. The designs so far are a bit of a departure from older digimon and characters (multi-color hair on humans and brighter outfits; sharper geometric shapes instead of organic ones and more use of colors on digimon such as Gekkomon) but we are seeing a return to the ensemble cast each with a digimon partner formula, which was always what earned each season its best praise. We'll have to wait and see how it ends up though.