Out of all the Ninjago themes, I've always had a soft spot for the Green Ninja theme. It's just a simple easily recognizable theme, but the reason why I love it so much is because of how many variations it goes through throughout the show.
It starts out as a normal heroic motif almost always going high to signify the mysticism of the Green Ninja. But over the course of the series it becomes more grounded as the Green Ninja and Lloyd himself become more self-actualized. It even goes through more fun and sort of silly variations. The one I can think of at the top of my head is from The Island where Lloyd plays distraction catch with Zippy so he could sneak and rescue the ninja.
My absolute favourite variations (besides the really cool and badass ones, because those are obvious) are when it goes lower. A great example of this is in S8 I think during the True Potential episode where Lloyd locks the other ninja and goes to face Garmadon alone, you can very clearly summarize what he's thinking from just the sound of his theme. It's in low and kind of dragging notes when it suddenly jumps back into action. Another version, which just about made me jump up when I realized it, is towards the end, and during the credits too, of the episode when we see Oni Lloyd for the first time. It's a theme that sounded oddly familiar even if I never heard it before until I realized that it's just the Green Ninja theme turned on its head to sound more sinister and villainous. I LOVE how they didn't make a new theme for "evil" Lloyd but instead rearranged his theme to sound a bit more like it, but it is still the same motif.
You can practically hear the theme adapt to its corresponding character in a way that few themes have and I just think that's really cool.
