Which season of the show do you think is the best?
For me, I'll have to go with Season 2. It expanded on certain aspects of Season 1 like Scrooge's connection to Della Duck, the mother of Huey, Louie, and Dewey, the aftermath of the Shadow War, and well written backstories (Flintheart Glomgold included). Season 1 was also great especially when it came to the dynamics of the McDuck family.
Season 3, on the other hand, was the weakest although it was still good overall with the finale being particularly solid as it wrapped up some loose ends. That being said, it had some characters that could've been written out, some of the humor lacking the spark, and some rushed pacing.