I’ve only watched up to season 8/9, but I remember the ol days when would watch all the episodes on YouTube. I still loved pirates, so I would always want to watch the pirate ninja crossovers. My favorite season is the one with nadakhan, the Jeanie that makes misinterpreted wishes. It’s the only season where the villain truly wins, but at the same time something stupid like a wish can just take it away.
The thing I most wished for was a cross over with Ninjago and chima, and there was even an episode where they traveled to the chima realm but with only a few seconds of interaction.